Horrible banging noise in engine
Thread Starter
Racer
Joined: Jun 2010
Posts: 251
Likes: 1
From: Edwardsville IL
Horrible banging noise in engine
The car has new heads, pushrods, rockers and intake manifold. The engine seems to be running fine, but there is an extremely loud banging noise. Watch the video and you can see. The valve springs that are in these heads are 1.5" single springs. Could the noise be one of the valve springs binding? Thanks for the help.
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
ARE WE ALL listening to the same clip ........ Engine cranks STARTER drags as it fires up and as it disengages you here a Bang ,, then it bangs again and he shuts her down ..
How on earth is that a valve or push rod ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
How on earth is that a valve or push rod ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
The duration of the video is too short to really determine what's going on. But whatever it is, it don't sound good. (Sorry for the poor grammar)
Thread Starter
Racer
Joined: Jun 2010
Posts: 251
Likes: 1
From: Edwardsville IL
It is 100% not the starter. The clip is short, but it keeps banging after the starter disengages. '75 looks like he's correct. Pulled the valve covers and one of the rockers is so loose it is hanging off the side of the spring. Time to readjust all the rockers. Thanks for all the help, I will post again if that doesn't fix it.
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Thread Starter
Racer
Joined: Jun 2010
Posts: 251
Likes: 1
From: Edwardsville IL
Pulled the plugs, rotated the engine by hand, no weird noises. Then pulled the coil wire and turned the engine with the starter, still no noises. Pulled the rockers and checked the pushrods, and they are all good.
2026 Loser of the Year
Joined: Sep 2013
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From: New Or-leens Loo-z-anna
Good to hear! Did you notice if the individual rocker studs are pulling out of the heads....or do you use the shaft-mounted roller rocker arms?
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
Put a timing light on it and see by moving from plug to plug if it happens on a particular cylinder. Sounds metallic and substantial to me. Measure the height of the push rods to see if one seems a little higher than the others. Maybe a lifter not smated to the cam correctly. At this point educated guessing.
Team Owner
Joined: Nov 2004
Posts: 20,715
Likes: 25
From: Sorrento Italy
The car has new heads, pushrods, rockers and intake manifold. The engine seems to be running fine, but there is an extremely loud banging noise. Watch the video and you can see. The valve springs that are in these heads are 1.5" single springs. Could the noise be one of the valve springs binding? Thanks for the help.
IMG 1168 - YouTube
IMG 1168 - YouTube
https://www.corvetteforum.com/forums...ed-please.html
I've pulled the valve covers and checked pushrods and rocker arm, everything is fine and smooth, valves measures intake and exhaust are exactly what the engine builder recommends...
I'm going to check the distributor if something happened there, if that would be the case the timing curve might have gone nuts...