# 68 GTO valve cover noise



## rob40999 (May 18, 2018)

Hello All: My 68 GTO valve cover is making a taping noise. I guess it's my
lifters??? How bad is this??? My #3 mecanic says it's nothing????
Can't the valve cover come off, and adjust the lifter's.

Engine is a stock 400cu. Need some advice..

Tks, Bobby


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## PontiacJim (Dec 29, 2012)

rob40999 said:


> Hello All: My 68 GTO valve cover is making a taping noise. I guess it's my
> lifters??? How bad is this??? My [URL=https://www.gtoforum.com/usertag.php?do=list&action=hash&hash=3]#3 [/URL] mecanic says it's nothing????
> Can't the valve cover come off, and adjust the lifter's.
> 
> ...



Mechanic #3 is an idiot and you need to stop going to him. Seeing that the rocker arms are held down by a rocker nut which is torqued in place, they can and do sometimes loosen up and even back off. So what will happen PontiacJim?

The nut can loosen enough to cause the rocker arm to go sideways. And why is this bad PontiacJim? Because as it goes sideways, it is no longer pushing up and down on the valve like it should. It can jam and bend the pushrod or even bust out the spring clip on the top of the lifter causing the lifter to come apart and drop small parts down into your engine causing major damage as the engine is rotating. 

Is that all PontiacJim? Nope. Should the rocker arm slip of at just th right angle and time, it could push down on the spring retainer instead of the valve, pushing the retainer far enough down that the valve stem locks pop out and the valve drops down onto the piston and shatters the piston and sends a piston/rod out the side of your block and you now need another engine.

So you think it could be serious PontiacJim? You won't know until you take your car to a qualified mechanic who works on older cars and knows what he is doing. You can take a chance and listen to the advice of mechanic #3 and IF it destroys your engine let mechanic #3 buy you a replacement because you trusted his advice. OR, pull the valve cover and re-torque all the rocker nuts to spec to know for sure. It could be a worn lifter/cam lobe, a worn rocker, or even bent pushrod. But, you will not ever know by guessing and relying on the advice of mechanic #3 who isn't worth a crap - its your engine, so go with what you feel is best. :crazy:


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## rob40999 (May 18, 2018)

Hello Jim: Got the info Great... 

1. Got a Question??? What is the torque for the nut???

2. If I pull the valve cover I would like to replace all the Nuts. I know they are probaly a locking nut like I use to use on the Aircrafts????

3. What size nut, and is there anything else I should look for.

4. I found an old mechanic who works on these car's, and he said, I could help with the adjustments of the Valves. 

5. Could you give me a short procedure on how to adjust the valves????

Thank you again. Bobby


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## 1968gto421 (Mar 28, 2014)

Bobby, if your '68 is stock, here are the nuts for you:

https://secure.amesperf.com/qilan/Detail_Web?part_num=N506&order_number_e=NDY2MTQxNw==
&web_access=Y

Here is the proper procedure to adjust the valves on a Pontiac engine:

VALVE ADJUSTMENT - PY Online Forums

Following the advice here from Pontiac builders will assist you greatly.:thumbsup:


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## 1968gto421 (Mar 28, 2014)

Also, your question will get more answers if you post under the 1974-1974 GTO engine discussions, not here on the 2004-2006 section. Thanks


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## PontiacJim (Dec 29, 2012)

1968gto421 said:


> Bobby, if your '68 is stock, here are the nuts for you:
> 
> https://secure.amesperf.com/qilan/Detail_Web?part_num=N506&order_number_e=NDY2MTQxNw==
> &web_access=Y
> ...




You are right, but the adjustment on the PY site is more for the adjustable valve train, and covers the factory style rocker arm nuts in the first 2 responses of the post - torque to 20 ft lbs. However, the rest of the info with regards to setting the lifters on the base of the cam and adjusting the rockers using the procedure pointed out will work.

You won't be adjusting the rocker arm nut as stated. Instead, you will simply torque each rocker arm nut to 20 ft pounds. Then move on to the next cylinder.

In doing this, I would remove each rocker arm and inspect it. Pull the rocker arm ball free and make sure the ball and cup it seats into doesn't look badly worn. Look at the end that sits on the valve stem and check for excessive wear. I would also pull my pushrod and examine it BUT, make sure you keep the orientation correct as the top ball will have seated/worn into the rocker arm and the other end will have worn/seated into the lifter cup and you don't want to flip these around. Inspect one pushrod at a time. If everything looks good, then put your rocker arm back on and torque down the nut. Then do the next cylinder.

Purchase the new nuts as someone could have adjusted the old nuts a few times and this can cause the rocker arm nuts to loosen up all the more. So I would get the new nuts and some valve cover gaskets if you think yours might be old.

If you see something that looks out of place, let us know and/or post a photo so we can help out if need be. :thumbsup:


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## rob40999 (May 18, 2018)

You guys are great. Buy a beer on me. LOL

I'm going to get the lifter's adjusted. Noise is very low. The noise does not increase in engine RPM's????? 

Will get back to you all. 

Tks, Bobby


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## BearGFR (Aug 25, 2008)

PontiacJim said:


> You almost got it right. The adjustment on the PY site is actually for poly locks, not the factory style rocker arm nuts.


Uh Jim, you must have been in a hurry...  The very first response in that referenced thread on PY, the one posted by 'grivera', and before the response that went into the detail poly-lock adjustment process, said:



"If by stock you mean all factory parts, including the bottle-neck rocker studs then torquing the nuts to 20 ft lbs is the method."
​
:grin2:0

Bear


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## PontiacJim (Dec 29, 2012)

BearGFR said:


> Uh Jim, you must have been in a hurry...  The very first response in that referenced thread on PY, the one posted by 'grivera', and before the response that went into the detail poly-lock adjustment process, said:
> 
> 
> 
> ...



Nope, saw that, but I was afraid that with having both methods in the same post, especially with the sequencing of the cylinders/rocker arms that followed the adjustable method that the OP would become confused only because there was more focus on the adjustable valves and seemed to me to almost mention the stock torque in passing. So in my opinion that piece was more about an adjustable valve train vs stock. 

The original question of that particular thread on PY was "What is considered the most accurate and reliable method of adjusting valves on a stock engine?" which is exactly what our OP asked - adjustment on a "stock" head. Then it rolled into "if it is not stock" and went on from there with how to do this. This was followed by the valve timing adjustment, valves open/closed, which can be used for the stock rocker arm nut torquing and not limited to an adjustable valvetrain which it was referencing - so that seemed a bit confusing. Then it went into roller cams, back to adjustments, and back to stock with additional questions and then adjusting the engine valves using the distributor.

Did you notice that the piece never mentions any kind of poly lock, what they are, or how to use them? "Your method works well on stock cam profiles." - So I wonder how many read this piece and use their stock rocker arm nuts doing the procedure outlined for zero lash. On a roller cam too? - "Did not know that Paul. I run a roller too...this winter I'm gonna use your method..already copy and pasted for reference.." 

You and I know all this stuff by heart, but for many, this kind of stuff can be confusing to the novice when you start throwing more than what was asked for as some don't know the difference between non-adjustable and adjustable valvetrain. So it would not take much for a newbie to think they have this adjustable valvetrain too and adjust as such. Sometimes you gotta clarify and simplify the things we understand because we have been doing it for so long. :wink2: :thumbsup:

This site really needs to have instructional "stickies" on some of the things and not be open for comment - just posted only and if any adjustments or changes need to be made or adapted, then ONLY an administrator can make these changes after being contacted and reviewing the changes to ensure they are relative. :yesnod:


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## integrity6987 (May 10, 2017)

*Add on question--*

I have never done this. I know my car had the engine rebuild by the previous owner and has a roller cam. Basic question: What would indicate this procedure should be performed? 
I think I could do this myself over the winter (if needed) and like the take your time and do it with the engine not running techniques outlined here an on the PY thread.

Thanks in advance.


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## BearGFR (Aug 25, 2008)

integrity6987 said:


> I have never done this. I know my car had the engine rebuild by the previous owner and has a roller cam. Basic question: What would indicate this procedure should be performed?
> I think I could do this myself over the winter (if needed) and like the take your time and do it with the engine not running techniques outlined here an on the PY thread.
> 
> Thanks in advance.


Very first thing, is that you MUST identify for certain whether or not you have a completely stock rocker arm and nut setup, or if any of those parts have been replaced with aftermarket parts.

If you have the stock system, then it is *not* adjustable. All you do is torque the nuts down to 20 lb ft. and you're done. If, and only if, you have an adjustable system do you go through any adjustment procedure.


Bear


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## rob40999 (May 18, 2018)

*1968 valve noise*

Hello All: 
I was wondering if I took off the valve cover, and just tighten down the nut to 20 foot lbs. would that be ok. My mechanic seems he want's to take down the engine now. When the engine is reved up to 2500 RPM's there's no noise. Just at Idel there is a small ticking sound. It seems my new mechanic wants to make this a big deal?????? When I was younger and had a 1968 442 with the same engine I remember just tighting the nut on top of the lifter????? There hydralic lifters?????? Am I going in the wrong direction?????

Another Idea is???? Could it be my timing is at 22 degrees BTDC at Idel. Base Timing) We went through this before. Could this be the Pinging in the engine???? Maybe back off the timing to 18 degrees BTDC, and see how it sounds???? This is just an Idea. Is Jim, and Bear out there... Help....

Tks, Bobby


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## BearGFR (Aug 25, 2008)

rob40999 said:


> Hello All:
> I was wondering if I took off the valve cover, and just tighten down the nut to 20 foot lbs. would that be ok. My mechanic seems he want's to take down the engine now. When the engine is reved up to 2500 RPM's there's no noise. Just at Idel there is a small ticking sound. It seems my new mechanic wants to make this a big deal?????? When I was younger and had a 1968 442 with the same engine I remember just tighting the nut on top of the lifter????? There hydralic lifters?????? Am I going in the wrong direction?????


Yes, you are going in the wrong direction. That 442 was an Oldsmobile with an Oldsmobile engine. This is a Pontiac with a Pontiac engine. **NOT** the same!
If "your mechanic" is insisting on pulling the engine and tearing it down without even doing the most simple and basic examination of what's going on, then he needs to be "your mechanic" no longer.



> Another Idea is???? Could it be my timing is at 22 degrees BTDC at Idel. Base Timing) We went through this before. Could this be the Pinging in the engine???? Maybe back off the timing to 18 degrees BTDC, and see how it sounds???? This is just an Idea. Is Jim, and Bear out there... Help....
> 
> Tks, Bobby


Maybe you have a timing problem ALSO, but that's not going to have anything to do with a ticking sound coming from the valve covers. It'll be a completely separate issue, if it's an issue at all. Question for you though: you said 22 degrees at idle. Is that with the vacuum line to the distributor connected or not?


Back to the rockers. I've included a couple of photos of what the factory rocker studs, balls, and nuts looked like. The first one shows the parts separate, the second one shows how they fit together. Note that everything is loose in both photos. 
In the first photo, the area in the red circle is the shoulder on factory Pontiac rocker studs. The rocker nut is just a plain old nut - nothing special. It's doesn't have any crimps or any other system on it that will make it stay in a certain spot. It is not adjustable. I didn't include the rocker arm in either photo so you could see how the parts fit together and what they look like. If this is the system you have on your heads, then they are not adjustable. Tighten all the nuts down to 20 lb ft. That's all that is required. The bottom of the rocker ball seats onto the shoulder on the stud, and torqueing the nut down to 20 lb ft keeps it there. Very simple.

Now look at the 3rd photo. This is what an adjustable rocker nut looks like. Notice the hex socket set screw in the middle. Once the proper adjustment has been set, that screw gets tightened down against the top of the rocker stud and "jams" things together so that the nut won't move.

The first order of business for you is to remove a valve cover and look things over in order to be sure what you've got in there.

Bear


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## BearGFR (Aug 25, 2008)

Also note that the photos I included in the previous post had to do with what the Pontiac factory setup looked like. One of the problems that you can run into when you buy a car from someone else, is that you can't REALLY know what all has been done to it. This can be especially true when it comes to the valve train, including the cam shaft. Sometimes people will have installed a more aggressive cam but will have "cheaped out" and NOT also changed the valve springs and other components that are needed to really take advantage of it and also to make it "live" a long a useful life. You may have an engine that has a nice aggressive sounding idle but won't survive at RPM under load for long, or will go into 'valve float' long before it can reach the RPM where the cam actually works well.

This is another reason to open it up and make dead sure of what parts you actually have in there. If there's any question, it's also not a bad idea to get a good dial indicator and stand, remove a couple of rockers, and measure the cam lobe lift. You won't be able to accurately measure other cam specs such as duration, lobe separation angle, and installed intake centerline without also using a degree wheel - and that's going to require at least pulling the balancer and timing cover - but you can measure lobe lift. This should tell you whether or not you 'probably' have a stock cam or an aftermarket one.

Bear


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## integrity6987 (May 10, 2017)

BearGFR said:


> Very first thing, is that you MUST identify for certain whether or not you have a completely stock rocker arm and nut setup, or if any of those parts have been replaced with aftermarket parts.
> 
> If you have the stock system, then it is *not* adjustable. All you do is torque the nuts down to 20 lb ft. and you're done. If, and only if, you have an adjustable system do you go through any adjustment procedure.
> 
> ...


looking under the valve cover through the oil access hole - I see red anodized roller rockers.


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## BearGFR (Aug 25, 2008)

integrity6987 said:


> looking under the valve cover through the oil access hole - I see red anodized roller rockers.


Can you also see poly-locks?

Bear


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