Squeaking from around valve covers
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Joined: Jan 2023
Posts: 50
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From: Denver
Squeaking from around valve covers
Alright, looking to source some ideas from everybody. I recently finished up a head swap along with new rockers and pushrods. Everything seems to be running pretty well except I’m getting this odd squeaking noise when the engine is up to temp and idling. Above idle it seems to go away and it doesn’t happen when cold.
At first I was worried the pushrods might be misaligned or not oiling but I’ve double checked them and clearances and oiling seemed to be fine after running it with the valve covers off. The odd thing is the noise didn’t happen with the covers off and it also goes away when I’ve got the covers back on and the dipstick pulled. This makes me think it might be a small vacuum leak but I’m not sure why it’d be missing when cold or revving if so. I’ll still be running that down.
Just curious if you guys have anything else you think I should be checking?
At first I was worried the pushrods might be misaligned or not oiling but I’ve double checked them and clearances and oiling seemed to be fine after running it with the valve covers off. The odd thing is the noise didn’t happen with the covers off and it also goes away when I’ve got the covers back on and the dipstick pulled. This makes me think it might be a small vacuum leak but I’m not sure why it’d be missing when cold or revving if so. I’ll still be running that down.
Just curious if you guys have anything else you think I should be checking?
Racer
Joined: Mar 2020
Posts: 387
Likes: 148
From: Langton, Ontario, Canada
2025 C4 of the Year Finalist - Unmodified
Because it happens when idling, it would seem to me to be a vacuum leak. Idle is when the vacuum is highest. Another telling indication might be if it happens when rolling down a long hill with no throttle being applied, and the engine is coasting at a higher rev speed than idle. I've replaced all my rubber lines with silicone lines, on my 85. Some of the ones I replaced looked normal, but would flatten to paper thin when vacuum was applied from a pump.
