# Knocking Noise Help Needed



## Lee Green (10 mo ago)

I have a high pitched "tapping" noise coming from the right side valve cover. I suspect a bad lifter/pushrod. Can these be replaced without removing the intake manifold? I'm running a factory 350 with about 180,00 miles on it. 
Thanks in advance to any help I can get!
Lee


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## Lemans guy (Oct 14, 2014)

First thing is pull the valve cover and look but don’t touch, use a flashlight take some photos and assess it. If a pushrod came off a rocker or you have a broken valve spring it could be an easy fix. But just don’t knock anything down in the valley pan.

remove it look assess photograph and come back lot’s of engine guys on here that can walk you thru steps for a solid repair


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## Lee Green (10 mo ago)

Thanks, I do appreciate that. I will take a look tomorrow.


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## Boomstick (Sep 13, 2021)

first, check your oil level. back when my 69 still leaked like an iraqi submarine, #4 cylinder would let me know the car was was a quart low on oil by making the same tapping noise. if its full, pull the valve cover and inspect everything. If nothing is out of place, drain one quart of oil and try a quart of trans fluid in the oil. tans fluid is full of detergents that will clean any gunk out of the oil system and is thinner so it will pump up a flat lifter. if that works, change your oil after about 100 miles...


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## armyadarkness (Dec 7, 2020)

If you have a Pontiac V8 with 180k on it, it should be tapping and knocking everywhere. That being said, as others mentioned, pull the valve cover and see if you see anything wrong. My motor is fairly new and it's got a noisy valvetrain.


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## Lee Green (10 mo ago)

Boomstick said:


> first, check your oil level. back when my 69 still leaked like an iraqi submarine, #4 cylinder would let me know the car was was a quart low on oil by making the same tapping noise. if its full, pull the valve cover and inspect everything. If nothing is out of place, drain one quart of oil and try a quart of trans fluid in the oil. tans fluid is full of detergents that will clean any gunk out of the oil system and is thinner so it will pump up a flat lifter. if that works, change your oil after about 100 miles...


Full of oil. I had the rear seal replaced 4 years ago. I will try your transmission oil idea. 
Thank you for your help!


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## Lee Green (10 mo ago)

Ok. 


Lee Green said:


> I have a high pitched "tapping" noise coming from the right side valve cover. I suspect a bad lifter/pushrod. Can these be replaced without removing the intake manifold? I'm running a factory 350 with about 180,00 miles on it.
> Thanks in advance to any help I can get!
> Lee


Ok. I've removed the valve cover. All my springs look good, all of my rocker arms have oil on them. However, I have 3 loose rocker arms. Is this as easy as tightening them? 2 are slightly loose, 1 is really loose. 
Thanks!'


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## PontiacJim (Dec 29, 2012)

Lee Green said:


> Ok.
> 
> Ok. I've removed the valve cover. All my springs look good, all of my rocker arms have oil on them. However, I have 3 loose rocker arms. Is this as easy as tightening them? 2 are slightly loose, 1 is really loose.
> Thanks!'


Yes, they get torqued down to 20-25 foot pounds. However, sometimes the rocker arm studs can pull up from the head as they are only press fit. Run a long straight edge across the tops of the rocker arm studs to make sure they are all equal. If so, re-torque the rocker arm nuts down.

If any have pulled up, I have heard you can knock them back down with a hammer, but I would be very careful so as not to mush the threads at the top of the rocker arm studs.


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## Lemans guy (Oct 14, 2014)

Good work, looks like you may have found the tapping with that loose rocker, and the other two getting looser!


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## Jared (Apr 19, 2013)

At 180K on the clock, I hope you're starting to save for a rebuild. Fingers crossed the loose rocker fix gives you a little more time. If you have to tap them back into place, as Jim mentioned, back the nut all the way back to the end of the threads where it is sitting just flush with the top of stem, and tap it with a brass hammer. That's probably your best shot at not mushrooming the ends.


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## Boomstick (Sep 13, 2021)

You could also drill and pin them to keep them from pulling out again


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## Lee Green (10 mo ago)

Lemans guy said:


> Good work, looks like you may have found the tapping with that loose rocker, and the other two getting looser!


I can't break them loose with a deep socket on my 3/8 drive. Forward or back! Oh well, time to start saving for a new motor!


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## Boomstick (Sep 13, 2021)

Lee Green said:


> I can't break them loose with a deep socket on my 3/8 drive. Forward or back! Oh well, time to start saving for a new motor!


righty tighty, lefty loosy


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## armyadarkness (Dec 7, 2020)

Lee Green said:


> I can't break them loose with a deep socket on my 3/8 drive. Forward or back! Oh well, time to start saving for a new motor!


Press in studs are just not good, if youre trying to have fun. My 66 Lemans had a mild cam and I used to break at least one stud a week. The nuts are meant to stay on... they're a sort of lock nut. So that might explain your extra effort.


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## Lemans guy (Oct 14, 2014)

Try some PB Blaster, or liquid wrench, let it sit, tap gently with a small hammer to vibrate, you know the drill, let it sit overnight, tap now and then and then revisit it…


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## Lee Green (10 mo ago)

Boomstick said:


> righty tighty, lefty loosy


Should I try a breaker bar? I don't wa t to cause any more damage. 
Thanks!!


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## armyadarkness (Dec 7, 2020)

My advice would be that if you don't know what you're doing or how it affects your engine, leave it alone until you're more comfortable. Right now you have some noise, but it's still running. 

It's easy to assume that they loosened up, but things that are "hard to remove" don't tend to loosen on their own. Is this noise only on start up? Is a lifter bad?

None of us are there to see or assess the situation.

One thing is for sure, those nuts come off when you turn them counter clockwise, and if they don't, then you have additional problems.

Do you own a torque wrench? If so, set it to 25 ftlbs and try to tighten them. That is their torque spec, so you know that they can take at least that much force.


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## Lee Green (10 mo ago)

armyadarkness said:


> My advice would be that if you don't know what you're doing or how it affects your engine, leave it alone until you're more comfortable. Right now you have some noise, but it's still running.
> 
> It's easy to assume that they loosened up, but things that are "hard to remove" don't tend to loosen on their own. Is this noise only on start up? Is a lifter bad?
> 
> ...


I do have a torque wrench, I will try your 25 pounds suggestion. I certainly agree with "I don't know what I'm doing". I don't want to make it any worse. 
If it's a bad cam, would the rockers on the opposite side be loose?
I won't have time till Monday to work on it again, but when I do I will keep you posted. 
Thanks so much for your help!


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## geeteeohguy (Feb 2, 2008)

If you can't get them loose then they didn't back off. Likely the camshaft went flat, causing the excessive clearances. You need to measure the pushrod lift to verify the cam is or is not flat.


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