# rattling noise at 2500-3000rpm



## Chris-Austria (Dec 23, 2010)

Hi!

I've got that rattling noise coming from the front of the car. I drove it to check for detonation but I guess it's something else. If I drive with a high gear and push the pedal it will not make any strange noises, but at 2500-3000rpm there is someting rattling.

I reved the engine in my garage and the noise is noticeable even while not driving, but only at 2500-3000rpm. (When I had the detonation problem, it was only hearable while driving)

So what could cause this noise? The engine has all of it's power and runs fine.
Could my Centerforce clutch make the noise? There are these centrifugal weights.. maybe they are loose?


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## Chris-Austria (Dec 23, 2010)

I checked it again.. the noise appears even at about 1500rpm but it's getting loader with more rpm, that's why I first thought it starts at 2500rpm. The reason I can't hear it later is probably because the engine itself is too loud.. but from 1500 starting to lets say 3000 the rattling gets louder with the rpm increase. (shifter at neutral)

Any ideas? Camshaft bearing? Valvetrain? Main bearings? Timing chain?


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## Chris-Austria (Dec 23, 2010)

Another update.. I put a screwdriver on my ear and the other side on some engine parts... The rattling seems loudest on (and near) the fuel pump. On the valve covers it sounds good, on the waterpump and timing cover it sounds fine, on the block (top) it sounds fine but on the oil pan and the fuel pump I think I can hear the same noise that appears at 1500rpm and up... 

How's that possible? Even without these information, what would you check?
I was also thinking about a timing issue but the sound is different from pinging (at least in my ears..)


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## GTO JUDGE (May 14, 2005)

Near the oil pan you say? Was the windage tray ever out? Dip stick tube? Long shot here, My thought was the windage tray. Maybe loosened up from not being torqued? All the metal with increased RPM more vibration which resonates a louder noise.


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## Rukee (Feb 8, 2007)

Could be a weak spring in the fuel pump.


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## geeteeohguy (Feb 2, 2008)

What Rukee said. Would be my first place to check, since the noise is coming from the pump area.


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## Chris-Austria (Dec 23, 2010)

How should I do that? Change the fuel pump to the old one? (the old one is almost new, but it has no return, that's why I didn't use it)
Windage tray was out when the engine was rebuild 2 years ago... dip stick is on the passenger side, my ears tell me there is more rattling on the driver side but I could test that with the screwdriver as well right where the dipstick tube goes down, thanks.


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## Chris-Austria (Dec 23, 2010)

The pump with the spring is the old edelbrock, the pump without the spring is the RobbMC that I removed today. 
Now I've got 2 questions...

1. Does the RobbMC doesn't have such a spring at all?!
2. If there should be a spring... how can I get it out of the engine now and can it hurt something?

If I tab the lever of the pump I can hear it knock, if I tab the lever of the Edelbrock (with the spring) it's perfectly silent. I guess that's the sound I could hear with the engine running, do you agree?


The next question will be... what kind of replacement should I get? Electric pump with regulator? If so.. what do you prefer? (I want to use my return line as well)


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## geeteeohguy (Feb 2, 2008)

Install the Edelbrock and see if the noise goes away.


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## Chris-Austria (Dec 23, 2010)

There still is a noise, maybe a little less...
If there was a spring.. maybe the spring makes the noise because it fell down into the oil pan?! 
I would really like to know if there should be a spring or not on the RobbMC pump...


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## BearGFR (Aug 25, 2008)

The RobbMc pump does have a spring, it's just in a different location. It's "on top" of the pump inside the smaller cylindrical housing on top of where the diaphragm is.

Since you hear a noise with both pumps (not surprising, RobbMc is good stuff) - it's probably louder with the RobbMc pump because it has a stiffer spring and "fatter" diaphragm to move more fuel.

My next suspicion would be the fuel pump eccentric on the front of the cam shaft. Perhaps it wasn't torqued down sufficiently and is in the process of working itself loose, or the eccentric itself could be failing.

You may have to really contort yourself to do it, but if you get the car up in the air a little and remove the pump, you might be able to use a combination of flashlight, mirrors, and a long screwdriver to "see" the eccentric and try to wiggle it around to see if it's coming loose or is damaged.

Bear


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## Chris-Austria (Dec 23, 2010)

thank you Bear!
a friend of mine has a small camera that can fit into the fuel pump hole, i'll try to locate the eccentric and check it.
after a cold start i'll have to wait about 1 minute until i can hear the rattle.. can you explain why?
and if i have to remove the cam.. can i do this with the engine in the car? (or can the eccentric be reached if i only remove the timing cover?!)

its making me sad to have engine problems.. again


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## BearGFR (Aug 25, 2008)

Yes, it can be done with the engine in the car. The timing cover has to come off. Unless you can get to the plugs on the side of the block and drain the coolant out of the block though, it's going to dump coolant down into your oil pan when you start to remove the cover so be prepared to deal with that. (Thorough oil drain, fresh oil, fresh filter, and DON'T turn the engine over until you do that so as to avoid pumping any coolant up into the oil system).

It might be something else completely though. That was just something that came to mind from your description.

I had mine back out on me in my car to the point where the eccentric was just spinning on the bolt and not moving the pump at all. They don't run real well with no fuel pump... 

Bear


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## Chris-Austria (Dec 23, 2010)

I'll try to wiggle it through the hole.. if it seems tight.. what else should I check?

It's really strange.. the "knocking" is louder on the fuel pump than on any other part of the engine that I can reach with the screwdriver-to-ear-method.

Thank you for the instructions on fastening the eccentric, I hope that is the source of the noise.. I'll need some hours for this job but I got all parts and gaskets I need already at home. I fear that other reasons for this sound might not be that "easy" to fix... am I right?


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## Chris-Austria (Dec 23, 2010)

I removed the fuel pump again and here is what I found:



















I hope the quality is good enough... I tried to point with a screwdriver on what I guess should be the eccentric. On the second picture it's the "round silver-gold part" on top of the picture. Is this my eccentric? 

I can move this part from left to right on the picture... away from the engine so to say. It will not move very far, but noticeable. What do you think? Is this a lose eccentric or something else?!


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## PontiacJim (Dec 29, 2012)

Yes, that is the fuel pump eccentric. I don't know how much movement it should have, but not much. Personally, it looks too "shiny" where it rides on the pump arm, but it might just be the photo. I wonder if the RobbMc pump puts greater pressure on the eccentric which may be putting a higher load on the ring the eccentric rides/spins on. The camshaft retainer has a slot/hole for oiling and has to be installed correctly to squirt oil to the chain/gear and I suspect the eccentric. See the attachment. Do you know if this was installed correctly?

You can go front-to-back, will it go up-down as it might be worn on the inside dia due to lack of lubrication? Just my thinking as I am just coming up with things to check.

Also, I would turn the engine by hand (or have your buddy do it) and watch the timing chain/gear operation just to check that as well since you can see inside. You might spot something that isn't the pump at all. I left the lower tube that goes inside the engine for the dipstick off only because my engine did not have one as it had been previously rebuilt by someone else and I didn't know about the tube. Put in my dipstick and it was right into the crankshaft throws. It briefly made noise I could not figure out until it broke off in the engine. Then one day I went to check the oil level and figured out what the noise was. Luckily, no damage and I got the broken piece out of the pan. However, a much shorter dipstick that only allowed me to check for the "full" level only!:lol:


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## Chris-Austria (Dec 23, 2010)

I can try if it goes up and down tomorrow, but it "wiggles" like Bear suggested.. The dipstick is the same as always.. I can remove it and listen but I Never had an issue with it.

My guess was that if this is the eccentric (like you confirmed) and it is bolted onto the camshaft, it should not move front-to-back at all, am I wrong?! I'll tell you if i can lift it up with the screwdriver when Im back at the garage.


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## BearGFR (Aug 25, 2008)

Yessir, that's the eccentric you're looking at. The outside of it that you can see is actually a shell/ring that spins on the insert that the bolt goes through, and into the cam. When properly installed, that insert has a shoulder on it that fits around the nose of the cam, and also a pin that rides in the cam gear key-way. When everything is 'right' the nose of the cam actually protrudes just a few thousandths of an inch past the face of the cam gear so that the inner part of the eccentric can center itself around the cam. You may be able to move the outer ring back and forth, in line with the center axis of the cam ("front to back" in terms of the engine) but it should be just a tiny bit of movement. If you can feel any "slop" at all side to side or up and down, then that may be the source of the noise. Also, like Jim pointed out. That retainer that he posted a photo of has an oiling hole in it that must line up with a corresponding oil passage in the front of the block. If that's not installed correctly, then the eccentric won't get enough oil and will wear fairly rapidly - eventually failing completely.

Also, that's a half-inch bolt going into a thick piece of metal (cam shaft). You don't really have to worry about getting it "too tight" if it turns out that you do need to take things apart to work on it - and some red loc-tite isn't a bad idea either.

















http://2.bp.************/-mreNMSelGU8/ThUaNTmbNdI/AAAAAAAAAMo/h65Yf7MTyoQ/s1600/001.JPG
http://www.ebay.com/itm/1964-Pontia...r_Truck_Parts_Accessories&hash=item259688fa56
Bear


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## Chris-Austria (Dec 23, 2010)

I was able to move it about.. hard to say... 2mm? (Front-back)
Now that I know the fuel pump is good I had to think about why I can hear the noise that good at the pump.. maybe its the eccentric that makes the noise as you said.. will I have to remove the timing cover to be sure I guess?

Can you explain "Slop" to me?  Im not sure if I understand it correctly to be bald to tell you if I can feel the slop..


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## Chris-Austria (Dec 23, 2010)

Update:

I was in the garage and tested it. I used a little magnet (don't know how it's called.. looks like a pen) to "wiggle" the eccentric. 

Results:

1. I can move it that far from front to back to hear it "hit the metal"
2. If I try to move it up/down I cannot access it properly with the screwdriver and with the magnet it will just turn around. (I also used the screwdriver to turn it around.. there is almost no resistance)

Questions:

1. Is that too much movement?
2. Should I be able to turn the eccentric without turning the camshaft??
3. If the eccentric can be turned without turning the engine, why does the eccentric turn if I manually turn the engine? (I tested it.. doesn't make sense to me... I can't explain how the pump can work at all if the eccentric can be turned without turning the engine..)


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## BearGFR (Aug 25, 2008)

Chris-Austria said:


> Update:
> 
> I was in the garage and tested it. I used a little magnet (don't know how it's called.. looks like a pen) to "wiggle" the eccentric.
> 
> ...


(Sorry, sometimes I forget that American slang can confuse folks. By "slop" I mean "slack - looseness - a lot of movement in all directions")

1. Front to back - no that's not too much, as long as it's only the outer ring that's moving and sliding back and forth on the insert. If the insert itself is moving, that's not good.
2. Yes, definitely. The ring should spin freely on the insert. In operation with the engine running the outer ring doesn't move much (if any) once it makes contact with the pump arm. That way it just pushes on the pump arm while the insert "turns" inside of the outer ring. If it were to rub on the pump arm, both pieces would wear a lot more.
3. Because with no pressure on the outer ring from the fuel pump arm, the oil film is viscous enough, the clearance is tight enough, and the outer ring is light enough that the insert is able to "drag" the ring along with it. 

Again --- this MIGHT not be the cause of the noise you're hearing. It's all just guess work at this point. Can you hear the noise with the car running but not moving? 

Before tearing down the front of the engine to check out the eccentric, I'd be tempted to try to "rig" a temporary gravity feed fuel system with a small container of fuel that I could hang on a stand or something, higher than the engine, so that fuel could feed into fuel line to the carburetor(s) without needing a pump. Make a temporary cover to block off the fuel pump mount on the side of the timing cover so that it doesn't "puke" oil from there, and then run the engine to see if the noise goes away, or at least changes significantly. There's a little work involved in rigging all that up that but it's easier than digging into the front of the motor. BE SAFE! don't hang the fuel directly over the engine, make sure all the connections are secure and that nothing can fall over, have a fire extinguisher handy, use just a small amount of fuel... Fire is NOT your friend! :nono: (How well I know... :nopity

Bear


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## Chris-Austria (Dec 23, 2010)

Thank you Bear!
It's hard to say if the insert has movement, I can't reach it.. only the outer ring. So it's not a bad sign that I can spin the outer ring and if the movement of the outer ring isn't too much I'm wondering if that's the problem. Still the noise is pretty loud on the fuel pump and for example almost not hearable at the timing cover, valve cover or waterpump.

I'll try to run it without the fuel pump like you said. I need to run the engine for 1-2 minutes until I can hear the noise usually.

I can hear the noise while driving and while not moving. I had the feeling it's almost gone at 4th gear while driving, but that doesn't make sense to me.. maybe it's just imagination.
(I thouhgt maybe the clutch with the weights have something to do with the noise, but why would I be able to hear it without a gear and the car idling in the garage?!)


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## Chris-Austria (Dec 23, 2010)

I tried it like you said. Result:

The noise is still there even without the fuel pump. Maybe it's not that loud but I can hear it pretty good. It's coming from that region but I can't locate it exactly.

When I start the engine there is a short rattle.. like 1 second. After that the engine runs fine and quiet and 1-2 minutes later it will start to make this noise... I can hear it best still at 2000-3000rpm. (car not moving.. but it's the same same noise if I drive it)

What else should I check?


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## BearGFR (Aug 25, 2008)

So, if the noise is still there without the pump, and coming from the same place (is it still the loudest if you listen to the pump mounting flange on the timing cover?) Then it most likely is not the pump eccentric.

I just thought of another way to get some more info. What's the frequency of the noise? How often does it happen? (Maybe connect up a timing light and compare the frequency of the noise to the flashing of the light). If it's happening "in time" with the light, then you know it's happening once every 2 crank revolutions (the same rate that the cam turns, and the distributor turns - so that points to something in the valve train or ignition or something that "operates" at that same rate). If it's happening twice as fast as the timing light flashes, then it's "in time" with crank shaft and that points to something associated with the main rotating assembly.

Just for grins, check all your exhaust manifold/header bolts to make sure they're tight. A leak there can sound like a 'tick', and if the escaping gas just happens to be "aimed" at the fuel pump area...

It may be time to go "Sherlock Holmes" on this one. 
"... when you have eliminated the impossible, whatever remains, however improbable, must be the truth." -- Sherlock Holmes

Bear


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## Chris-Austria (Dec 23, 2010)

I'll go to a shop and tell him everything I know and what you told me. I don't have a timing light to check that, but he surely can do it. Thats a great idea!

I checked the exhaust and couldn't find leaks, I even put my hand near all tubes to feel the air.. but it seems to be good.

Do you think the alternator or steering pump can make such a noise? Should I remove the belts and try?

EDIT:

I've tested it again and I now think I can hear the sound pretty good at the driver side valve cover (maybe I forgot to listen to it before.. sorry) and at the fuel pump again (I reinstalled everything).
If I listen to it at the same speeds (idle and about 2000rpm) the driver side is "ticking" and the passenger side doesn't really sound conspicuous. Is it possible that this sound is coming from the valve train and made it's way down to the fuel pump because it's on the same side? If I start to think about it.. yesterday I only listened at the passanger side valve cover.

If I give it more rpm's the noise gets faster and louder. I made a short Video, maybe you can hear it. Hard for me to descirbe the frequency, but if high is 0 and 10 is dull it's probably a 6.
I once had a problem with a spark plug wire.. it broke and I fixed it. Maybe it's now broken inside, would one missing spark make such a sound? It was the wire of cylinder #7 or #5, can't remember it for sure.

https://www.youtube.com/watch?v=ssNGB8CyiG4


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## 68-GTO (Oct 20, 2013)

i hear a unnormal sound in the video.
for me it hears like a shrink camshaft.
when one cam top is bad, the sounds like this one...

or it can be a bad lifter... something like the valvetrain...

that would explain the short rattle after start cranking, which you wrote...


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## PontiacJim (Dec 29, 2012)

Sound can certainly travel. Time to pull the valve cover and see if you have a loose rocker arm. You can then start it up and observe to see if all rockers are working or hear the noise. It could be a simple adjustment or you may have a bent pushrod or collapsed lifter. 

Roller cam or flat tappet cam? 

Careful as oil is about to squirt all over, so be ready once you start it up with the valve covers off.


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## Chris-Austria (Dec 23, 2010)

It's a flat tappet (hydraulic)... 2 years old.
I'll remove the cover and check if I can see something suspicious. I won't try to repair it by myself if it's a problem with the valvetrain, but I'd really be happy to know where this noise is coming from.

I already started to think about a roller camshaft if the flat tappet is worn out.. but I'd be more happy to repair it and keep my engine the way it is now.


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## Chris-Austria (Dec 23, 2010)

Update.. again 

I removed the valve covers.. on the passenger side the threads of the rocker arms are equal in lenght, on the driver side 2 threads look a lot shorter. (on the pic you can't see #1, it has about the same lenght as #5).

All in all the driver side threads look different in lenght, at #1 and #5 you can see a lot less of the thread and the others don't seem to be all equal as well... compared to the passenger side, where all threads have about the same lenght.

Can this be a Problem? And how should I proceed? I don't want to make things worse by turning the nut's and make them too tight.

Driver side:









Passenger side:


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## Chris-Austria (Dec 23, 2010)

update #2:

I've been at the shop with my car. He said it sounds like a piston, not like something in the valvetrain. How's that possible? It never ran too hot, oil pressure is good, I don't push it until it is fully warm... 2 years since it was rebuild 

Any ideas how I can confirm that I have to remove the engine?

Oil consumption doesn't seem unnormal for me.. if the piston can "wiggle", wouldn't it use and burn oil? (blue-black smoke from the exhaust?)
The engine will rattle very short on a cold start, 1 sec. or even less. After that it will run quietly even if I rev it up to 3000rpm and after another minute or two it will start to make this noise from the video, good to hear up from about2000rpm. Will a wiggling piston make the noise like I describe it or would it make the same noise all the time at all rpm's? (and especially when cold?!)


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## 68-GTO (Oct 20, 2013)

i dont think that this can be a piston.
but ok, in live thats can sounds like different.

i would turn the nuts from the rocker "a little" bit when the enige runs, that show you when the sounds change, that the fail is there.

or you have a stethoscope?
that a great thing by failure like this!


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## Chris-Austria (Dec 23, 2010)

I just have a screwdriver and my ear  A friend of mine will check the rockers today, I dont think I should screw it up just because I dont know how tight or loose they should be..

I removed the oil to see how it smells and looks like.. nothing special with it but I only drained 4,4 Liters instead of 5 that I filled in in May14. I'll now fill in 5 again, but I guess that is not the problem. (with oil filter change)

Would a piston make the noise at all rpm? And would it get louder with more rpm? And would it be silent until the engine has warmed up a little? And would it rattle on a cold start for 1sec or less?! Many questions


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## 68-GTO (Oct 20, 2013)

a piston can tilt, but that is not that sound.
perhabs your store mean that a bearing are bad, perhaps the upper rod bearing, that is than always and not only by a few other conditions.

when you turn the rocker nut only 1/4 turn (loose or tight is equal) nothing can happens, but that show you if the sound change.
when yes youre right, and when not you can turn the nut back.

this way i would go first.
Bear what you think??
i think you understand me....


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## BearGFR (Aug 25, 2008)

I listened to your video. It's an odd sound, "deeper" than what I'd expect to hear for valve train noise yet it seems to be "in time" with the cam rotation. First thing I'd check for would be to see if you've got "slop" in any of the pushrods. Turn the engine over by hand using a wrench on the crank bolt (valve covers off). When you see #1 exhaust valve just starting to open, check #1 INTAKE valve by trying to move the pushrod up and down. There should be perhaps only the slightest amount of travel - zero is preferable. Work your way around the engine in firing order sequence (1 8 4 3 6 5 7 2) checking each intake valve when you see the corresponding exhaust just starting to open. Now go around again, this time check each EXHAUST valve just after the corresponding INTAKE has reached full open and is just beginning to close.
If you find one or more that are loose enough to allow you to move the pushrod up and down "quite a bit", then that just became your prime suspect.

Flat tappet cam --- what oil have you been using and does it have (or have you been adding) ZDDP in it?

Thinking now about how you say it does it at first start, then goes away, then comes back. That -could- be consistent with a bad lifter that's slow to respond to oil pressure when the engine first starts up, and then when the oil gets nice and warm (and thin like it's supposed to be) it can't maintain itself and starts to open up the clearance. A wiped cam lobe would be noisy all the time, I'd think.

Bear


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## Chris-Austria (Dec 23, 2010)

Thank you again Bear and 68-GTO.
My friend listened and also thinks it's down in the crank area. But I'll check the valvetrain by myself like you told me, just to be sure. Maybe I'll try to borrow a timing light and see if the noise happens in time with the flashing light or if it's faster. 
A bad spark plug or spark plug wire could not be the source I guess?

If there is a bad piston or bearing... do my symptoms seem to make sense?

I use Valvoline VR1 20w50 with about 1200ppm ZDDP. (Mineral oil)


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## ppurfield001 (Jan 21, 2008)

Chris-Austria said:


> There still is a noise, maybe a little less...
> If there was a spring.. maybe the spring makes the noise because it fell down into the oil pan?!
> I would really like to know if there should be a spring or not on the RobbMC pump...


I had an issue like that and it came from the fact that the drive shaft became unbalanced when it lost a balancing weight. Once the drive shaft was balanced, no more rattle. Good luck.


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## Chris-Austria (Dec 23, 2010)

I started to check the pushrods, but I have some questions again.

On this picture:









This is cylinder #3 intake and exhaust.. for example.. as soon as the spring where the arrow points at starts to move down, I have to check the intake valve?
And for the exhaust valves.. First the intake valve lets say at cylinder #3 again will start to open (spring being compressed and going down) at the time when it's fully open and the side with the spring is starting to go up again, I have to check the exhaust valve?

I did check intake valves by this method for cylinder 1,3 and 5 until now. #3 is good, no movement. #1 and #5 will move like on this video I made:

https://www.youtube.com/watch?v=qh2to_3EdVM


Is this too much? Does it indicate a problem with bad lifters?


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## Chris-Austria (Dec 23, 2010)

Ppurfield, did you hear the noise even if you didn't drive the car?
Can the driveshaft make this noise if I just rev the engine in my garage?


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## ppurfield001 (Jan 21, 2008)

Chris-Austria said:


> Ppurfield, did you hear the noise even if you didn't drive the car?
> Can the driveshaft make this noise if I just rev the engine in my garage?


Sorry Chris, I missed that point in the string of e-mails. In my situation, rattle noise only surfaced when the car was running on the road. No noise at idle. Sorry for the confusion...


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## Chris-Austria (Dec 23, 2010)

No problem, every idea is appreciated 
I'd be happy to have the same problem you had instead of what might happend to my engine...


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## PontiacJim (Dec 29, 2012)

I don't like that one rocker nut having the allen adjusting screw further down than the rest. This would mean that the adjusting nut is higher than the others in order to get the allen screw tightened up in that lower position. I think they should all be the same based on my experience. (you do have screw in rocker arm studs?).

If the adjusting nut is higher on that rocker arm stud, then your rocker arm is sitting higher which means less pressure on the valve lifter and too much play at the rocker arm. This will cause it to "tick". I would look at this first thing. 

Back the allen screw out like the others. Then start the engine. Put your finger on the rocker arm stud, sometimes you may feel it "clicking". Compare it to another one and see if you notice a difference in the feel. While it is running, you can back the adjusting nut out until you hear an audible clicking. This means your rocker arm is too loose. Now, begin to tighten it back down. Tighten until you do not hear the "ticking". Wait a minute for the lifter to bleed down and "normalize". If it begins to click again, tighten a little more until it goes away. Again, wait a minute for the lifter to "normalize". If you no longer hear any clicking, turn the adjusting nut 1/4 turn more and while holding the nut, tighten the allen screw down to lock the nut into position.

Also observe all the pushrods as they should all be spinning. If you see one that is not, it could be over tightened. Your hydraulic lifters spin (roller lifters do not) on the cam as the cam rotates and so your pushrods should also rotate.


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## Chris-Austria (Dec 23, 2010)

Thank you very much Jim.
I was just in the garage and I now know what I did wrong.. on each cylinder side the first and the last valve's are exhaust valves and the two in the middle are exhaust valves. so to say 1,4,5,8 are exhaust and 2,3,6,7 are intake valves, is that correct?

So if for example #1 starts to go down on the spring side, I have to check #2 and when #2 is fully down on the spring side and starts to move up again I have to check #1.

I did that with quiet a lot valves and found out they all travel except on cylinder 6 and 8, they seem to be better than the rest. 2 and 4 will travel a little, but not as much as for example both valves on the drivers side at all cylinders.

I can try to adjust the 2 nuts that are higher than the rest (both on the drivers side). But I'm not sure how to explain why a lot of pushrods can be moved pretty far, the one from my video isn't the one that travels the most!

I don't know if many lifters can be out of alignment at the same time or if maybe the cam is that bad?! How do you explain that?
Can there be detonation in some cylinders because of bad valve timing causing this noise that seems to deep for typical valvetrain-noises?

Edit:

I removed the spark plugs now and because it is 3am I cannot put it together and test it.. but how do you think will a loose spark plug sound like? I was able to remove #5 spark plug just by hand.. turned very easy. By the way.. the plugs look good.. little white with a brown touch, not burned or deformed.


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## 68-GTO (Oct 20, 2013)

a loose sparkplug sound like a burnt header gasket.


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## BearGFR (Aug 25, 2008)

Chris-Austria said:


> https://www.youtube.com/watch?v=qh2to_3EdVM
> 
> 
> Is this too much? Does it indicate a problem with bad lifters?


That's sure looked extremely loose to me. I'd nearly bet that's contributing a lot to the noise you're hearing. It doesn't necessarily mean that the lifter is bad, it could just be out of adjustment.


Bear


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## Chris-Austria (Dec 23, 2010)

Bear, I found most of the pushrods will travel at least as far as on the video. Only cylinder #6 and #8 are better.

I'm not sure if I can adjust all of them.. maybe I'll just make all of them worse. I tried it on #1 and #4 cylinder... #1 was "ticking" pretty loud after that so I adjusted it while the engine was running until the ticking stopped, that's a completely different sound and was easy to figure out where it comes from.
The cylinder on the passenger side now also "ticks" but not very loud. But the funny thing is, I think the deeper noise has traveled.. now I can hear it on the passenger side as well, before I couldn't.

There are now some questions:

1. Why does almost every pushrod travel at the point where it should have preload? (Did they all loose the alignment or may I have a lot of bad lifters or even a bad camshaft??)
2. Can the deeper noise result from something in the valvetrain under these circumstances? Still all people that could hear it said it's not a typical valvetrain noise.
3. What happens if the timing chain slipped? Can this be a reason for all of the pushrods (valves) to be out of alignment and cause that noise?
4. What if the pushrods are bent? (one or more) Will that cause this travel and or the noise if it hits the head or block?


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## Chris-Austria (Dec 23, 2010)

I now adjusted all the valves like I was told, it runs fine but the "rumble" like in the 1st video is still there. Maybe it's a little bit less, I can't confirm that tonight because I don't want to wake everybody around.

I'm running out of ideas...


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## PontiacJim (Dec 29, 2012)

Chris-Austria said:


> Bear, I found most of the pushrods will travel at least as far as on the video. Only cylinder #6 and #8 are better.
> 
> I'm not sure if I can adjust all of them.. maybe I'll just make all of them worse. I tried it on #1 and #4 cylinder... #1 was "ticking" pretty loud after that so I adjusted it while the engine was running until the ticking stopped, that's a completely different sound and was easy to figure out where it comes from.
> The cylinder on the passenger side now also "ticks" but not very loud. But the funny thing is, I think the deeper noise has traveled.. now I can hear it on the passenger side as well, before I couldn't.
> ...


Don't over think this, you'll worry yourself to death. Step at a time.

Watched your video. Too much play in my opinion.

1. Hydraulic lifters use oil to pump up the plunger inside the lifter. You need some preload on the plunger to make it work correctly. I always adjust the lifters with car running as you can hear the lifter "clicking" when there is not enough preload and things are too loose. Do each rocker arm at a time on each head. I usually go 1/4 turn on the adjusting nut after the "clicking" stops. Some say to go 1/2 turn. If you know who made your lifters, you can email them and ask what they recommend, 1/4 turn or 1/2 turn after the "clicking" has stopped.

2. It is always hard to determine what is wrong simply by noise or sound. My brother had a thumping noise that was very audible while the engine was running. He could not determine where it was coming from, but it was louder on the starter side and down inside the engine. He thought it was a bad rod or bearing. Turned out it was actually a bolt on the torque converter that bolts to the flywheel. It had backed out and was striking the block. Sometimes the only way to know is to pull the engine apart or wait until it breaks so you know what it was. Waiting for it to break can be costly.

3.Looked like in your photos you had a double roller timing chain. It would not slip as it is too new and they are pretty tough. If it were out of timing, your valves still work in the same way, they just would be opening sooner or opening later in relationship to your pistons reaching their top point of travel. This is done to fine tune a cam and is called "retarding the cam" or "advancing the cam." So if it slipped, you would know it and you would see it in your engine timing.

4.If your pushrods were bent, you may or may not know it. Very simple check. You can pull them out and roll them on a piece of flat glass. If it is bent at all, you will see this when you roll it on the glass pane. If the pushrod was bent enough to hit the block or heads, it would be obvious. A bent pushrod this bad would most likely slip from under the rocker arm and not operate the rocker arm. I had this happen. It would not make any noise as you describe as it goes up and down and if it hit, would bend.

5. You could have a bad cam lobe. They can go bad and basically they round off and do not operate the rocker arm up and down at the full travel it is supposed to. If the cam lobe wore down, I would think it would be "clicking" because this would give you play at the rocker arm. You can check this with a dial indicator and measuring the lift at the rocker arm.

6. You could also remove your intake and the valley pan to look inside at the cam/lifters if you needed to. But again, you may find nothing wrong.

7. You might want to buy an engine stethoscope as they are cheap. It is better than the screw driver to the ear technique.

8. Again, adjust the rocker arms and get them correct before doing, or thinking anything more. You are going to loose too much sleep over this! HaHaHa.


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## Chris-Austria (Dec 23, 2010)

I have a double roller timing chain, like everything else almost new.
I also removed 2-3 pushrods where they had the most travel.. they look good. 

I adjusted the rocker arms with a cold engine.. removed the spark plugs, turned it over 2 times and started to set every rocker arm. After starting the engine again it sounded just fine... until it got warm.. after that I could hear the deeper knocking again 

The engine doesn't "click".. or maybe I misunderstand the term.. do you think a bad cam lobe could make that noise from my video?

I could readjust the rocker arms again with the engine running, but something tells me that won't change a thing since they don't travel any more and there is no "ticking" in the rocker arms as if they are too loose.

I can't help it.. sometimes I have the feeling the sound is still pretty loud somewhere around the fuel pump eccentric.. but even without the fuel pump it made this noise. Probably I'll now have to pull the engine and open it to find the problem. 

I'm just curious if there can be something bad with a piston. Still the engine runs without any noises until it's warmed up. 2-3 minutes after the cold start today it began to make that noise again.. the "good" news is I couldn't hear the short rattle at Startup.

Edit:

I now have 2 new ideas... 

1.) I read that a piston pin knock will be better notable as the engine gets hotter and that there is a double knock. This double knock is what I described as "rattle". Maybe that's the problem? And if so, how can this be fixed?! (I think this is more likely than a piston slap because a slap would be more notable if the engine is cold and the sound is described as "hollow", I think my engine sounds different)

2.) Also I read that a loose vibration damper can cause such a noise and because I can hear it well on the front of the engine, maybe I should check that as well?! Or will a loose vibration damper only make such a noise while the car is in gear and driving?


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## Chris-Austria (Dec 23, 2010)

I've now read many articles about wrist pin noise and I guess it sounds like the noise I got. What do you think? Possible? (no noise when cold, starts to make noise when getting hotter and makes 2 "knocks" every time it appears.

I'll now have to drop the engine anyway, but what can you tell me about Pontiacs with wrist pin noise? What can cause this and how do I solve it? Did my cylinder walls suffer from that? And if not.. will I have to remove all the pistons and rods to check for damages and replace only the bad ones or should I replace all of them?

If I have to remove the engine, I don't want to use the old oil pan again, do you know a good oil pan with no clearance issues that will hold about 7quarts instead of the 5 I have at the moment?


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## geeteeohguy (Feb 2, 2008)

A jumped timing chain on a Pontiac will bend the valves and basically not run. It only happened with really worn out gears. Not your problem here. What Pontiac Jim said. Go through the steps. I watched the video. You have too much travel. Either a bad lifter or a flat cam or the valve adjustment is not correct. Dial indicator time. Posting a video of the noise as it occurs may be helpful. From what I've seen lately, flat cams and bad lifters are very common due to the poor materials they are now made from. A LOT of failures.


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## Chris-Austria (Dec 23, 2010)

I got rid of the travel. All rockers are adjusted now, only 3 had that travel from the video. The others were good, I just did the test wrong at first time because I thought it's always first intake then exhaust valve on each cylinder but it's exh/int, int/exh, exh/int, int/exh. That's why only the cylinder # 3,7,4,8 were tested correctly. Now all rockers seem to work fine for me, no ticking and no travel on the intake valve as soon as the exhaust valve of the same cylinder will start to open and no travel on the exhaust valve if the intake valve of the same cylinder will start to close again after fully open.

Maybe it will be best to check the valvetrain visually before removing the engine just to be sure, but something tells me the noise is coming from a littler lower in the engine.

The noise occurs as a double "knock" what I called "rattle" and it will not be there as long as the engine is cold... not any sign of the noise! After 2-3 minutes I can best hear it if I rev the engine to more than 1500rpm, maybe it will disappear at higher rpms (above 3000) but maybe I just can't hear it because the noise don't get louder, but the engine will be pretty loud (normal sounding) at these rpm's.

Oil pressure is 70psi when cold, 60psi after 2-3 minutes and always above 25psi if the engine is really hot at idle (after driving on the Autobahn...). At more than idle rpm the oil pressure will be as high as 60psi most of the time.

I read that a wrist pin can make such a noise.. the mechanic guessed it could be piston slap because of the frequency of the sound (he said it doesn't sound like valvetrain) but I read that piston slap will be louder when cold and gets better when hot... in my case the engine is perfectly silent when cold and starts to make the noise when warmed up. The noise will not be there when warmed up at idle... at least it's not easy to hear.. you need to rev it to about 1500rpm to be easily able to hear it. (it's always the same noise and frequency, if I rev the engine in my garage or drive it on the street)

What do you think?


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## geeteeohguy (Feb 2, 2008)

I think you need to post a video of the noise, if you can. You are correct, piston slap will go away warm as the pistons expand. What you are describing to me sounds like possible rod knock.....too much clearance in one connecting rod bearing. You can verify this by disconnecting one ign. wire at a time (and only one) and rev the engine to 1500 and see if it goes away on that cylinder. If the knock goes away when you eliminate the spark, it is a bad rod bearing. Loose/worn rod bearings tend to behave exactly as you described. This is an easy, 5 minute test to perform. If the noise is still there after you have gone through all 8 cylinders, it is not a bad rod bearing.


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## Chris-Austria (Dec 23, 2010)

I'll try that, thank you!
What if the wrist pin is knocking, will that noise also go away if I eliminate the spark in the noisy cylinder?
My rods are almost new, Scat H Beams.. so they rather go bad down on the crank or at top where it holds the piston?

Its the same noise as on my first video I posted, if you want another one I could do that but I thought its better not to run it too often now.

Im wondering what has to be done if a rod bearing or the wrist pin causes the noise.. replace bad part with new part, change all rods or pistons, oversize the cylinders again (4.160 at the moment)..


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## chuckha62 (Apr 5, 2010)

The last double knock that I had to deal with was fortunately not as bad as I feared...

Mine was an oil pan that got deformed a little bit and pushed into the throw of the crank ever so slightly. One knock was the rod end, the second knock (180* apart) was the counter balance. Is there a chance your pan got deformed while you were working on your car? Have you listened down at the pan? If it is you would REALLY hear it down there, so I doubt this is it.


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## Chris-Austria (Dec 23, 2010)

I can hear it at the front of the pan and as well at the place where the fuel pump is mounted at the timing cover.. but the fuel pump eccentric won't be the problem I guess because it makes the same noise without a fuel pump.
The pan isn't visibly deformed.. could you see the dent in the pan when you had the knock?


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## geeteeohguy (Feb 2, 2008)

Ok.....I listened to the video. I would do the 5 minute pull-a-plug-wire test to verify that it is NOT a rod knock. I've run into rod knocks that sound a lot like yours, and only did it at light cruise rpm, too. If that fails, it's stethescope time.


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## Chris-Austria (Dec 23, 2010)

I'll do that the next days. When I start the engine I want the stethoscpope ready and a timing light to see if the knock is as fast as the crank or as fast as the valvetrain.

If the rod knock isn't there with a cold engine and almost not to hear at idle.. do you think it will cause a lot of damage in the engine?
I will for sure tell you what caused the noise as soon as I found it, even if I have to remove the engine. The shop will remove my engine Friday in a week.. I can search for the problem until then and if I want he will first remove everything on top before he removes the engine from the car.

I would like to know how much money will be needed to repair it, that's why I ask what parts will have to be replaced if it is for example a rod knock or a wrist pin. I can easily calculate a new camshaft kit + small parts... but I have no idea what a bad piston pin or rod bearing will cost. (I just bought an Audi for daily driving, can't spend too much on the engine now..)

Since I read that a bad piston pin will cause a double knock and is better to hear with a hot engine I can't get that pin out of my mind.. I also read that if I remove the plug wire from the cylinder with a bad piston pin the noise won't disapppear.. maybe it will even be louder.. don't know why, but do you think that's correct? I'll also check for that when I do my testings..


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## geeteeohguy (Feb 2, 2008)

Again, before you worry about costs, possible scenarios, parts, when to pull the engine, you need to do the simple 5 minute rod bearing test. Why worry about 'what if'? Waste of time. Just pull the wires and verify if it is or isn't a con rod.


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## Chris-Austria (Dec 23, 2010)

A friend who has some experience with such engines listened today and he said it sounds very much like piston pin noise. 
I don't know how "deep" a bad connecting rod (big eng) would sound like, but he thinks it's deeper than valvetrain but not as deep as a problem on the big end.

The noise is a double knock and if you listen carefully it's not as fast as the crankshaft, but he said that piston pin knock is an exception and will not make noise as fast as the crankshaft... what do you think?

If it's the piston pin(s)... I guess I shouldn't run the engine any more. Do the pistons harm the cylinder walls if it's piston pin wear and how is this normally being solved?

Oh sorry I forgot, the noise doesn't seem to change if I pull a wire.. no matter which one.


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## Chris-Austria (Dec 23, 2010)

I made 2 new Videos:

after a coldstart.. no knock:
https://www.youtube.com/watch?v=iQOL4imma4A

after 3-4 minutes.. knock: (not at idle, starts at about 1300-1500rpm)
https://www.youtube.com/watch?v=LFbg2CG8KMU

I would say it's a double knock and there is no noise until warmed up, that's why I think it's no piston slap.. more possible it's a connecting rod bearing or the piston pin. If I pull spark wires the noise doesn't change..


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## geeteeohguy (Feb 2, 2008)

Not likely a con rod bearing if no noise change. Looks like you'll have to tear it down and measure everything, or drive it until it breaks,and then you'll KNOW what it was! Good luck. I _hate_ this kind of problem.


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## PontiacJim (Dec 29, 2012)

I agree with geeteeohguy, doesn't sound like a connecting rod bearing, at least by my experiences. Sounds like something is hitting. I don't know if you used a windage tray, but I have read and seen photos of the factory windage tray breaking loose and hitting the crank and worse.

I think if it were me, because you have a lot of money in the engine, I would have to pull the engine and look inside. If you catch it now, it may be a simple fix.


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## Chris-Austria (Dec 23, 2010)

I hate this kind of problem as well... but you're right, I'll have to remove the engine to find the noise 

Jim, do you think it doesn't sound like a connecting rod bearing at all because of the frequency or because of the fact it doesn't change if I pull the spark wires? Or both?

I don't want to risk a fatal damage because of a rather small problem.. maybe it's the windage tray, the fuel pump eccentric bolt, the piston pin or whatever.. at the moment the engine runs strong so I guess it hasn't done too much damage... at least I hope so.


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## PontiacJim (Dec 29, 2012)

Chris-Austria said:


> I hate this kind of problem as well... but you're right, I'll have to remove the engine to find the noise
> 
> Jim, do you think it doesn't sound like a connecting rod bearing at all because of the frequency or because of the fact it doesn't change if I pull the spark wires? Or both?
> 
> I don't want to risk a fatal damage because of a rather small problem.. maybe it's the windage tray, the fuel pump eccentric bolt, the piston pin or whatever.. at the moment the engine runs strong so I guess it hasn't done too much damage... at least I hope so.



My experience with a Pontiac engine and '73 Mercury Capri V6 was that the rod bearings went bad and it had a very audible and hard knock -oil pressure went low as well.

I don't know what a wrist pin knock sounds like as I never had that experience.

I know pulling the engine out and tearing it apart will be no fun and a lot of work, but you will find out what it is and it could be something very simply, something you were glad you found before it really damaged your engine, or you may find a larger problem that needs to be fixed, but you at least have not destroyed your engine waiting too long.

Hopefully it will turn out to be something very simple and you will laugh at it later. This is how we all learn.


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## Chris-Austria (Dec 23, 2010)

I really hope it's not a big thing.
I'll ask the shop to first remove the radiator and fan, remove the intake manifold and timing cover and check the bolt for the fuel pump eccentric or bad lifters. If everything looks good maybe it's time to remove the engine.

I guess disconnect the driveshaft, remove the bolts from the transmission and remove the hood will be necessary to be able to lift the engine up and out of the car?

How does it sound if a valve is bad? Maybe it's detonation because one of the cylinders (or two) have bent valves? This would probably need a hot engine until the fuel can burn even if the sparkplug doesn't fire...


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## Chris-Austria (Dec 23, 2010)

I got new ideas. Someone told me the noise doesn't sound rhytmic enough for a rod/piston related noise.
I should check timing chain, waterpump, crank balancer and starter. What do you think if you listen to the 2nd video? I guess it's worth a try.


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## ppurfield001 (Jan 21, 2008)

Chris-Austria said:


> I got new ideas. Someone told me the noise doesn't sound rhytmic enough for a rod/piston related noise.
> I should check timing chain, waterpump, crank balancer and starter. What do you think if you listen to the 2nd video? I guess it's worth a try.


Check the gas pump as well. Since the noise comes when the engine is running between 2500 and 3000 RPM and not in other RPM ranges, it could be the gas pump. Years ago, I also remember replacing a timing chain that made some noise before it broke.


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## Chris-Austria (Dec 23, 2010)

The fuel pump itself is good for sure, I checked that and ran the engine with another pump. Maybe the eccentric is bad, but the noise was still there even without a pump at all.

Do you think you can hear a rhytm in the noise? I'm not sure if it's a constant knock or if it's rather unryhtmic. 

Would a bad wrist pin, rod bearings, main bearing make the noise cold and hot? I know piston slap would be loudest when cold.. but there is NO noise when cold... it needs a warm engine to make the noise, so that should remove some possibilities from the list?!

Can 2 bad lifters make a noise like a bad wrist pin (double knock) and only when the engine is hot? Funny thing is I found a video on YouTube where they show the sound of a stretched timing chain.. it sounds very like my noise.. as far as you can tell by watching a video.


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## PontiacJim (Dec 29, 2012)

Maybe take the front of the engine off first because you said it sounded like the front. Double check everything. 

If you find nothing, leave it apart, and take off the intake/carb, and remove the valley pan so you can see the lifters/cam.

If you find something, you won't have to pull your engine. If you don't find anything, you had to pull off these parts anyway. At least you can inspect and see those things you feel it could be at this time.

It still could be a bad lifter/cam.

1.)Did you adjust each lifters/rocker arm with the engine running? 

2.)Did you contact the lifter manufacturer to find out what the correct preload is? 

3.)Have you tried putting a dial indicator on each and every rocker arm to see if the movement of each is the same as you crank your engine over(with coil wire pulled so it won't start)?


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## Chris-Austria (Dec 23, 2010)

On Friday the car will go to a shop, he can check all these things that I can't. I'll contact Comp Cams to find out the preload and give him all the information I got here.
He doesn't want to remove the engine but he'll do it if necessary. So I hope he'll find something in the valvetrain.. or even chain/fuel pump eccentric. He can remove the timing cover before he removes the engine as well I guess just to be sure everything is good there.

Maybe I could do some of the work.. remove the intake and so on, but if I do I'm not sure if I can find the problem even if it is there and it will make it hard to get the car out of my garage if the engine is half-apart... because if there is nothing bad on the upper part of the engine I'll have to take it to the shop anyways. (or if I have a bad cam.. I cannot put in a new one by myself)


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## PontiacJim (Dec 29, 2012)

Chris-Austria said:


> On Friday the car will go to a shop, he can check all these things that I can't. I'll contact Comp Cams to find out the preload and give him all the information I got here.
> He doesn't want to remove the engine but he'll do it if necessary. So I hope he'll find something in the valvetrain.. or even chain/fuel pump eccentric. He can remove the timing cover before he removes the engine as well I guess just to be sure everything is good there.
> 
> Maybe I could do some of the work.. remove the intake and so on, but if I do I'm not sure if I can find the problem even if it is there and it will make it hard to get the car out of my garage if the engine is half-apart... because if there is nothing bad on the upper part of the engine I'll have to take it to the shop anyways. (or if I have a bad cam.. I cannot put in a new one by myself)


OK. Sounds like you are in good hands. Your mechanic should be able to find the problem. Keep us posted and make sure you let us know what it is -we all want to know at this point.:thumbsup:


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## Chris-Austria (Dec 23, 2010)

I'm really curious. As soon as I know it, I'll post it, maybe including a picture or video if I can. Still I hope it's something in the upper part of the engine.


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## chuckha62 (Apr 5, 2010)

Chris-Austria said:


> I can hear it at the front of the pan and as well at the place where the fuel pump is mounted at the timing cover.. but the fuel pump eccentric won't be the problem I guess because it makes the same noise without a fuel pump.
> *The pan isn't visibly deformed.. could you see the dent in the pan when you had the knock?*


Sorry it took so long to get back to you... My pan was deformed and it could be seen once I knew to look for it. I suspect your problem isn't what I experienced.

Good luck to you!


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## Chris-Austria (Dec 23, 2010)

Hi!

The engine is now removed and I found the problem... 
I haven't checked all the bearings yet but one was looking bad (dark gold color instead of silver). Cylinder #4 rod bearing is the problem.. there was play and the dark color so we checked it first and it made groves into the rod itself and the crank. The others dont have play and look good but we'll check that tomorrow.
Pistons are good and the bores don't show any signs of wear.. they are 2 years and 3000 miles old.

And I didn't imagine hearing something from the front of the engine.. the timing chain was rattling as well.


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## PontiacJim (Dec 29, 2012)

Chris-Austria said:


> Hi!
> 
> The engine is now removed and I found the problem...
> I haven't checked all the bearings yet but one was looking bad (dark gold color instead of silver). Cylinder #4 rod bearing is the problem.. there was play and the dark color so we checked it first and it made groves into the rod itself and the crank. The others dont have play and look good but we'll check that tomorrow.
> ...


Thanks for the update. Let us know what was wrong with the rod, installed wrong? out of round? not enough crush? or?

What caused the chain to rattle, loose? hitting something?


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## Chris-Austria (Dec 23, 2010)

The mechanic will work on my engine soon. I'll let you know what caused it.
He said probably it was a lubrication problem that ruined the rod bearing. How it is possible to have a rattling chain (it's loose.. not hitting something) is very strange, it's a Comps 3110 and has 3000 miles on it. I'll get the billet timing chain set from Butler Performance this time.


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## geeteeohguy (Feb 2, 2008)

I'm betting that the machine work on #4 rod was not up to par from the get go. Probably not resized correctly. Virtually ALL of the aftermarket rods need massaging before installation.....if this one was a little egg shaped, there you go. I might be wrong, but my gut is feeling this one. A lubrication problem generally wipes out ALL rod bearings.


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## 646904GTO (Feb 10, 2008)

I know you found a bad con rod bearing but looking at your pictures you are running aluminum heads and it looks like you need longer pushrods. the visual geometry and set screw height makes it look like the rocker is down to low and the spring is hitting the rocker. Just sayin'


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