C3 ticking / knocking sound.
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No, that slight wear on the side of the shaft looks perfectly normal. I think wear on the ends is really what your looking for.
a side note. I had a annoying clicking sound in my 77 engine awhile back. Turned out to be excessive end play in the distributor shaft. Pulled the distributor, removed the gear. Reshimed to spec. (Summit sells shims). Back in, reset timing, clicking gone.
a side note. I had a annoying clicking sound in my 77 engine awhile back. Turned out to be excessive end play in the distributor shaft. Pulled the distributor, removed the gear. Reshimed to spec. (Summit sells shims). Back in, reset timing, clicking gone.
Thread Starter
Intermediate
Joined: May 2020
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From: Netherlands
Le Mans Master
Joined: Apr 2011
Posts: 6,284
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From: Hermosa
You got the pushrod out, you could start the motor and see if the ticking is gone. Sure a little oil may come out the hole if you don't put the fuel pump back in place, and you'll need to replenish the carb. of fuel. But you don't need it to run long to confirm right?
Le Mans Master
Joined: Sep 2001
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From: Unreconstructed, South Carolina
FWIW
OE FP PR length = 5.75"
-add-
on rare occasion, the cam's fuel pump eccentric aka lobe becomes grossly worn & non-functional.
OE FP PR length = 5.75"
-add-
on rare occasion, the cam's fuel pump eccentric aka lobe becomes grossly worn & non-functional.
Last edited by jackson; May 11, 2020 at 04:27 PM.
Le Mans Master
Joined: Aug 2017
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From: Cool Northern Michigan
Back to the drawing board fellas. Its not the fuel pump pushrod.
Going back to post one: I am leaning towards a valvetrain issue.
Corvette 1977,
did you visually witness the valvetrain at idle? In others words, removing one valve-cover at a time and watch the valves, rockers, retainers, springs while running. After it cools down, grab each and every rocker and spring and check for excessive lash, bent pushrod or a broken valve-spring. Sometimes a broken valve-spring damper is almost impossible to detect and does not affect compression. Look real close. Then do the other side.
If you have a set of oil spray retainers clips for the rockers, all the better. Don't rev it, just watch for unusual action.
Going back to post one: I am leaning towards a valvetrain issue.
Corvette 1977,
did you visually witness the valvetrain at idle? In others words, removing one valve-cover at a time and watch the valves, rockers, retainers, springs while running. After it cools down, grab each and every rocker and spring and check for excessive lash, bent pushrod or a broken valve-spring. Sometimes a broken valve-spring damper is almost impossible to detect and does not affect compression. Look real close. Then do the other side.
If you have a set of oil spray retainers clips for the rockers, all the better. Don't rev it, just watch for unusual action.
Last edited by HeadsU.P.; May 11, 2020 at 05:14 PM.
Le Mans Master
Joined: Apr 2011
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From: Hermosa
Back to the drawing board fellas. Its not the fuel pump pushrod.
Noises are hard to diagnose on line. Tick, Knock, clack. Certain metal on metal noises have a very distinctive sound, Like valve train noises or rod knocks, others are more mysterious, but it take an experienced ear to hear the difference. And even then you can be fooled sometimes.
On video it can be misleading as well. Hard to discern without being there.
I have a pair of the stethescope thingy's too, but don't find them particularly useful usually. The hose trick seems to work better. Or if access is possible long screwdriver with handle to the head.
In any case the area of the noise needs to be narrowed down to refine our guesses.
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Le Mans Master
Joined: Aug 2017
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From: Cool Northern Michigan
You are right on. Its near impossible to use years of diagnostics knowledge by watching / listening to someones video. You have to be there to witness what's going on.
All us posters can do really is guess/ give ideas.
All us posters can do really is guess/ give ideas.
Thread Starter
Intermediate
Joined: May 2020
Posts: 46
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From: Netherlands
It's not fuel pump pushrod, the sound is still there.
I listened with a hose and long screwdriver, but did not hear any abnormal sound.
I measuring all lifts to determine if a lobes /lifters and there is no deviation there.
I remove one valve-cover at a time and watch the valves, rockers, retainers, springs while running. After it cools down I grab each and every rocker and spring and check for excessive lash, bent pushrod or a broken valve-spring but there are no abnormalities.
I listened with a hose and long screwdriver, but did not hear any abnormal sound.
I measuring all lifts to determine if a lobes /lifters and there is no deviation there.
I remove one valve-cover at a time and watch the valves, rockers, retainers, springs while running. After it cools down I grab each and every rocker and spring and check for excessive lash, bent pushrod or a broken valve-spring but there are no abnormalities.
Thread Starter
Intermediate
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From: Netherlands
Dr. Detroit
Joined: Mar 2012
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From: New Braunfels Texas
Well, at least you know what it isn't and sometimes that info can be very useful.
When you lashed it......how many turns after zero lash did you go?
What method did you use?
Run the engine at night in a dark garage too....sometimes a plug or wire zap to ground sounds like a tick......
Jebby
When you lashed it......how many turns after zero lash did you go?
What method did you use?
Run the engine at night in a dark garage too....sometimes a plug or wire zap to ground sounds like a tick......
Jebby
Last edited by Jebbysan; May 12, 2020 at 01:16 PM.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
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From: New Braunfels Texas
Go aorund and check them again using the TDC of each cylinder method. Start at TDC #1, lash those two valves I and E...zero lash then 1/2 turn....then go through the firing order (1)-8-4-3-6-5-7-2 and do each cylinder at TDC for that cylinder. You need to mark the balancer at 90 degree intervals for this......each 90 degree after #1 is the next cylinder in the firing order.......wont hurt to check and it is free. If you somehow lashed it at, say, a 1/4 turn for each one after zero lash....they will be noisy.
Jebby
Jebby
Last edited by Jebbysan; May 12, 2020 at 02:07 PM. Reason: spelling
Le Mans Master
Joined: Apr 2011
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From: Hermosa
You could try lashing them while it's running if you can, depends on the rockers in use and if you can get a socket on them without it grabbing the socket. Some engines apparently make a big mess while running with the valve covers off, mine doesn't, yours might not either. Some guys do end up lashing the valves while it's idling to finally make sure they are all tightened 1/2 to 1 full turn down to try to eliminate that as a source of valve train noise.
Does any of the rockers have the pivot nut tightened down a lot further down to get lash than the others? This could be a sign of a worn/wiped lobe on a cam or bent pushrod. Have you removed the pushrods to check for straightness by rolling it on a flat surface?
Just what I can think of if your going to be in that area anyhow.
Does any of the rockers have the pivot nut tightened down a lot further down to get lash than the others? This could be a sign of a worn/wiped lobe on a cam or bent pushrod. Have you removed the pushrods to check for straightness by rolling it on a flat surface?
Just what I can think of if your going to be in that area anyhow.
Thread Starter
Intermediate
Joined: May 2020
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From: Netherlands
You could try lashing them while it's running if you can, depends on the rockers in use and if you can get a socket on them without it grabbing the socket. Some engines apparently make a big mess while running with the valve covers off, mine doesn't, yours might not either. Some guys do end up lashing the valves while it's idling to finally make sure they are all tightened 1/2 to 1 full turn down to try to eliminate that as a source of valve train noise..
I gave a quarter turn three times because otherwise the engine would stop.
There is no difference in the adjustment.
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