# Does anyone recognize this knocking noise?



## kevin1727 (Aug 4, 2021)

428 new engine build. About 350 miles on the car since it was finished. 








Intermittent knock at idle?


Sounds like something tapping on the valve cover.




youtube.com


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## Mine'sa66 (Oct 30, 2019)

From your other thread....there is definitely something wrong. From all your symptoms, it sure appears like you have a valvetrain issue and listening to that, it sounds like you have one as well. I'd pull the valve cover on the side the noise is coming from. I suspect it will be very enlightening.
It's not a difficult thing to do.


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## Baaad65 (Aug 29, 2019)

Not sure if this is correct but an intake valve not opening won't let any air/fuel in the chamber hence the "like new plug" looks, might have two intake rockers off or very loose. You might discover that and with an easy fix and totally redeem everything then you will be doing a dance 👍


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## BLK69JUDGE (Jun 10, 2010)

A lot of shakin goin on there

2 plug wires mixed up ?


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## Sick467 (Oct 29, 2019)

I'm sticking to my guess in your other thread...loose rocker. Disclaimer: videos are awesome, but hard to diagnose over the net. I have been unlucky enough to have switched up some plug wires and pulled hair over it, but that clickity-clack sure sounds like a rogue rocker!


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## Baaad65 (Aug 29, 2019)

Sick467 said:


> I'm sticking to my guess in your other thread...loose rocker. Disclaimer: videos are awesome, but hard to diagnose over the net. I have been unlucky enough to have switched up some plug wires and pulled hair over it, but that clickity-clack sure sounds like a rogue rocker!


Same, on my old 455 and a car guy looked at it and said it was a bent valve...turned out my dumb ass crossed two wires 🤪


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## Baaad65 (Aug 29, 2019)

Here's where I pulled out a lot of my hair after buying a motor on ebay and it runs like a hit and miss because of the unknown resistor wire giving the motor 9 volts. Boy I wish I was part of the forum for that, I could have saved money on the hair club for men 🤯motor on 9 volts


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## kevin1727 (Aug 4, 2021)

Sick467 said:


> I'm sticking to my guess in your other thread...loose rocker. Disclaimer: videos are awesome, but hard to diagnose over the net. I have been unlucky enough to have switched up some plug wires and pulled hair over it, but that clickity-clack sure sounds like a rogue rocker!


BINGO!

I'm going to post more photos and videos on the other thread.








Frustrated with builder


Here's a photo of the plugs when I removed them after one hour of driving at mostly highway speed right after the 750 Edelbrock was installed. #1 and #6 are clean but the rest are dirty. Yes, #1 has a tiny chip or mold imperfection on the center insulator. If it is a carburetor problem why...




www.gtoforum.com


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## Baaad65 (Aug 29, 2019)

Hell ya! I suspect that may be it 👍


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## Jared (Apr 19, 2013)

Score! Fingers crossed this does it.


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## Baaad65 (Aug 29, 2019)

...I know it's trivial but when you put the covers back I seal them to the cover and not the head.


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## PontiacJim (Dec 29, 2012)

kevin1727 said:


> BINGO!
> 
> I'm going to post more photos and videos on the other thread.
> 
> ...



Looks like the pushrod is all chewed up at the end. Suspect your others may be chewed up as well. We had a former member that had the same experience - chewed them all up as they were the wrong ones.









Central Virginia Machine Service (CVMS) Negative Review


WARNING! Do not send your engine to this hack! Well after almost a year of waiting to get this engine back from Jim L. @ CVMS including tearing it back down to a long block to fix things like rusted tins, cracked hub, leaking timing cover etc. I again had noise coming from the rockers and...




www.gtoforum.com





That would also be why the vacuum gauge needle was bouncing in your video. Are you sure the engine has been rebuilt? Lot of "junk" to the lower right of the rocker that went sideways and the heads don't look very clean for a rebuild.


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## Baaad65 (Aug 29, 2019)

Good catch, maybe it was loose for a bit and got hammered, ya mine looks cleaner than that after 2000 miles 🤔


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## Baaad65 (Aug 29, 2019)

PontiacJim said:


> Looks like the pushrod is all chewed up at the end. Suspect your others may be chewed up as well. We had a former member that had the same experience - chewed them all up as they were the wrong ones.
> 
> 
> 
> ...


Is that the shop that was used?


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## PontiacJim (Dec 29, 2012)

Baaad65 said:


> Is that the shop that was used?



No. That was a former member's experience, but if you look at the first post, that was what I was pointing out - pushrods were all chewed up and he had to rebuild the rebuilt engine again and get the correct pushrods. He also found other issues with the rebuilt engine - and this was from a very reputable Pontiac engine builder.


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## sameold01 (Jun 21, 2020)

#5 intake do you have something missing on top of the valve spring? Make sure the rocker bodies avoid touching the valve springs.


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## Jared (Apr 19, 2013)

sameold01 said:


> #5 intake do you have something missing on top of the valve spring? Make sure the rocker bodies avoid touching the valve springs.


Good catch. Could be a different style valve spring but kind of strange.


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## PKent (Mar 13, 2021)

kevin1727 said:


> 428 new engine build. About 350 miles on the car since it was finished.
> 
> 
> 
> ...


You can buy a cheap stethoscope for engines and it does help locating the noise.


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## Honeyharbour62 (Jul 15, 2018)

BLK69JUDGE said:


> A lot of shakin goin on there
> 
> 2 plug wires mixed up ?


Or plug wires arranged using Chevy information where the cylinder furthest forward on the block would be #1 which is not the case with Pontiac?


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## Honeyharbour62 (Jul 15, 2018)

BLK69JUDGE said:


> A lot of shakin goin on there
> 
> 2 plug wires mixed up ?


Or plug wires arranged using Chevy information where the cylinder furthest forward on the block would be #1 which is not the case with Pontiac. 

Oops, I should have read the whole post before chiming in. Hopefully all's well now.


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## kevin1727 (Aug 4, 2021)

Honeyharbour62 said:


> ......
> Oops, I should have read the whole post before chiming in. Hopefully all's well now.


Yep, 5 new pushrods and poly locks. The rockers are doing fine now.


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