Vibration?
Thread Starter
Instructor
Joined: Apr 2006
Posts: 243
Likes: 0
From: Canton MI
Vibration?
I have a pretty bad vibration at mid-high RPM that is definitely engine related. I have had others look at the car and is seems that everyone agrees that something is terribly out of balance.
Any opinion as to what it is? Damper? Flywheel? Internals? I'm hoping damper...easiest to replace...this needs to be fixed so I don't blow the engine apart.
Any opinion as to what it is? Damper? Flywheel? Internals? I'm hoping damper...easiest to replace...this needs to be fixed so I don't blow the engine apart.
Thread Starter
Instructor
Joined: Apr 2006
Posts: 243
Likes: 0
From: Canton MI
Increases with higher RPM, entire car shakes, two mechanics have told me they thought it was a damper or flywheel. Happens whether the car's in neutral or not...can't be driveshaft related. What else could it be?
Intermediate
Joined: Aug 2006
Posts: 31
Likes: 0
From: Lynn Ma.
I have a pretty bad vibration at mid-high RPM that is definitely engine related. I have had others look at the car and is seems that everyone agrees that something is terribly out of balance.
Any opinion as to what it is? Damper? Flywheel? Internals? I'm hoping damper...easiest to replace...this needs to be fixed so I don't blow the engine apart.
Any opinion as to what it is? Damper? Flywheel? Internals? I'm hoping damper...easiest to replace...this needs to be fixed so I don't blow the engine apart.
Russ
Thread Starter
Instructor
Joined: Apr 2006
Posts: 243
Likes: 0
From: Canton MI
Its a 3970010 block from a 1975 truck. It could be a 2 bolt or 4 bolt...they used both. No idea on internals but it was "rebuilt," whatever that could mean. The last owner used this block with the original L82 heads, original carb, etc. Beyond that, I don't know much about the engine itself. Oh, its a 350 (may be a 355 with overbore, not sure).
The car is a 4-speed. The only work I have done to the trans is replacing the mount and getting the speedo in working order...and a fluid change. Its a 3.70 rear end.
Hope that helps some...
Thanks
The car is a 4-speed. The only work I have done to the trans is replacing the mount and getting the speedo in working order...and a fluid change. Its a 3.70 rear end.
Hope that helps some...
Thanks
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Burning Brakes
Joined: Feb 2006
Posts: 1,024
Likes: 1
From: AL
check the harmonic balancer to be sure it has not separated or partially separated from the hub.
one way to check engine mounts: while in car with one foot on gas and one foot on brake, give it a little gas without letting car roll. with the hood open and a friend looking in the engine bay, he/she should see the engine stay in place. if it moves very much, the mount could be broken, you'll know. and also, don't run over your friend!
one way to check engine mounts: while in car with one foot on gas and one foot on brake, give it a little gas without letting car roll. with the hood open and a friend looking in the engine bay, he/she should see the engine stay in place. if it moves very much, the mount could be broken, you'll know. and also, don't run over your friend!
Drifting
Joined: Jan 2001
Posts: 1,841
Likes: 3
From: Halifax, NS, Canada
check the harmonic balancer to be sure it has not separated or partially separated from the hub.
one way to check engine mounts: while in car with one foot on gas and one foot on brake, give it a little gas without letting car roll. with the hood open and a friend looking in the engine bay, he/she should see the engine stay in place. if it moves very much, the mount could be broken, you'll know. and also, don't run over your friend!
one way to check engine mounts: while in car with one foot on gas and one foot on brake, give it a little gas without letting car roll. with the hood open and a friend looking in the engine bay, he/she should see the engine stay in place. if it moves very much, the mount could be broken, you'll know. and also, don't run over your friend!
Burning Brakes
Joined: Feb 2006
Posts: 1,024
Likes: 1
From: AL
Binnie77: And which foot does he put on the clutch
Answer: was multi-tasking, thanks
well forget that test - unless you have an emergency brake that really works. i kinda doubt it's the mounts anyway.
i've had pilot bearings go bad in those rpm ranges, but i would describe them as a high frequency very noisy vibration. either they make the noise or don't (when they began going bad). couldn't get the vibration with the car parked in neutral, but could with the clutch pedal depressed.
Answer: was multi-tasking, thanks
well forget that test - unless you have an emergency brake that really works. i kinda doubt it's the mounts anyway.
i've had pilot bearings go bad in those rpm ranges, but i would describe them as a high frequency very noisy vibration. either they make the noise or don't (when they began going bad). couldn't get the vibration with the car parked in neutral, but could with the clutch pedal depressed.