Ghost Engine vibration
Thread Starter
Instructor
Joined: Jan 2008
Posts: 163
Likes: 23
From: St Augustine
AK Events Coordinator
Ghost Engine vibration
L76 engine oscillating vibration. Moving or stopped.
Engine tuned/runs Perfectly.
Engine vibration in neutral or in any gear.
With water pump and alternator belts removed, still have vibration.
Push in clutch. Less vibration & Clutch whine but still there.
Vibration worsens as road speed increases .
Thoughts??
Engine tuned/runs Perfectly.
Engine vibration in neutral or in any gear.
With water pump and alternator belts removed, still have vibration.
Push in clutch. Less vibration & Clutch whine but still there.
Vibration worsens as road speed increases .
Thoughts??
Last edited by actionguru; Oct 31, 2016 at 02:31 PM.
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
L76 engine oscillating vibration. Moving or stopped.
Engine tuned/runs Perfectly.
Engine vibration in neutral or in any gear.
With water pump and alternator belts removed, still have vibration.
Push in clutch. Less vibration & Clutch whine but still there.
Vibration worsens as road speed increases .
Thoughts??
Engine tuned/runs Perfectly.
Engine vibration in neutral or in any gear.
With water pump and alternator belts removed, still have vibration.
Push in clutch. Less vibration & Clutch whine but still there.
Vibration worsens as road speed increases .
Thoughts??
Could be a worn pilot bushing letting the clutch disc run off center.
Thread Starter
Instructor
Joined: Jan 2008
Posts: 163
Likes: 23
From: St Augustine
AK Events Coordinator
vibration
L76 engine oscillating vibration. Moving or stopped.
Engine tuned/runs Perfectly.
Engine vibration in neutral or in any gear.
With water pump and alternator belts removed, still have vibration.
Push in clutch. Less vibration & Clutch whine but still there.
Vibration worsens as road speed increases .
Thoughts??
Engine tuned/runs Perfectly.
Engine vibration in neutral or in any gear.
With water pump and alternator belts removed, still have vibration.
Push in clutch. Less vibration & Clutch whine but still there.
Vibration worsens as road speed increases .
Thoughts??
Whine from area lessens with clutch pushed in.
Shifts good, no chatter or slippage.
But vibration above 45 mph escalates.
Last edited by actionguru; Oct 31, 2016 at 05:11 PM.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,146
Army
MikeM is right in nearly every case.....
But, to cover all the bases, I would check for misfires, correct plug firing order and motor mounts in addition to what he says... If the firing order checks out then pull one wire off a time and look for about a 200 RPM drop with the car idling...the cylinder that does NOT cause the drop is suspect...
But, to cover all the bases, I would check for misfires, correct plug firing order and motor mounts in addition to what he says... If the firing order checks out then pull one wire off a time and look for about a 200 RPM drop with the car idling...the cylinder that does NOT cause the drop is suspect...
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Thread Starter
Instructor
Joined: Jan 2008
Posts: 163
Likes: 23
From: St Augustine
AK Events Coordinator
vibration
engine work includes new spark plugs, plug wires, cap & rotor, points, new carburetor, new intake manifold gasket, valve adjustment, timing set.
vibration feels like it comes and goes every few seconds . Starts at idle all the way up through RPMs.
revving engine does not raise up from motor mounts
oil pressure 60 lbs
no knocks or dead miss
vibration feels like it comes and goes every few seconds . Starts at idle all the way up through RPMs.
revving engine does not raise up from motor mounts
oil pressure 60 lbs
no knocks or dead miss
Last edited by actionguru; Oct 31, 2016 at 08:07 PM.
Melting Slicks
Joined: Jun 2012
Posts: 3,115
Likes: 196
From: Wilton Ca.
I think that Mike is on to something regarding the pilot bushing. I base this assumption not so much on the vibration as to the fact that you've mentioned something about a "whine" a couple of times.
Gary
Gary
Drifting
Joined: Jun 2007
Posts: 1,552
Likes: 99
From: Lake Villa Illinois
St. Jude Donor '14
engine work includes new spark plugs, plug wires, cap & rotor, points, new carburetor, new intake manifold gasket, valve adjustment, timing set.
vibration feels like it comes and goes every few seconds . Starts at idle all the way up through RPMs.
revving engine does not raise up from motor mounts
oil pressure 60 lbs
no knocks or dead miss
vibration feels like it comes and goes every few seconds . Starts at idle all the way up through RPMs.
revving engine does not raise up from motor mounts
oil pressure 60 lbs
no knocks or dead miss
Gerry
Thread Starter
Instructor
Joined: Jan 2008
Posts: 163
Likes: 23
From: St Augustine
AK Events Coordinator
Yes.
Vibration was there before work was done.
Tried to cure vibration but no luck.
Whine is louder in neutral than should be as well.
pushing in clutch cuts sound of whine in half but still there
Vibration was there before work was done.
Tried to cure vibration but no luck.
Whine is louder in neutral than should be as well.
pushing in clutch cuts sound of whine in half but still there
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
If you have the transmission in gear and you don't hear the whine but put it in neutral with the clutch in, I'd guess your pilot bushing is worn, the clutch disc is still turning to make the noise. If that's the case, when you let the clutch out, the pressure plate can clamp the disc a little off center and make a vibration.
Drifting
Joined: May 2002
Posts: 1,420
Likes: 254
From: Hogansville ga
2021 C2 of the Year Finalist - Modified
had a 61 had the same problem years ago (but was an automatic) found it had a 400 flexplate (extra weight on it) maybe yours has a 400 balancer?? found problems with big blocks the same, 427 w/454 stuff and vice versa, also found 301 balancers on Pontiac 400's...all cause a balance problem.
Le Mans Master
Joined: Feb 2001
Posts: 6,317
Likes: 291
From: Ocala FL
I agree with Mike's pilot bushing. If the clutch has been replaced some time before you, and you have always had some vibration, I'm betting the clutch is out of balance. Over time, that will wear the pilot bushing and make it all worse.
Pressure plates are frequently out of balance by several grams, even when new. Most never notice or complain. But when you get a new pressure plate, you should have it balanced either with the flywheel and marked or have each balanced separately.
I bet a shop owner a free balance once if the plate was more than five holes off, because he swore it was balanced as it was new. When it came back, there were ten drill marks in it to balance it.
Also, people frequently surface a flywheel but never balance it. Surfacing theoretically should not affect balance, but it does.
Pressure plates are frequently out of balance by several grams, even when new. Most never notice or complain. But when you get a new pressure plate, you should have it balanced either with the flywheel and marked or have each balanced separately.
I bet a shop owner a free balance once if the plate was more than five holes off, because he swore it was balanced as it was new. When it came back, there were ten drill marks in it to balance it.
Also, people frequently surface a flywheel but never balance it. Surfacing theoretically should not affect balance, but it does.
Last edited by Procrastination Racing; Nov 1, 2016 at 09:54 PM.