1981 Corvette Vibration
Thread Starter
6th Gear
Joined: Jun 2021
Posts: 6
Likes: 2
1981 Corvette Vibration
Good evening. I have a 1981 Corvette with a weird vibration issue. When i start my car (and keep it in park) and push down on the gas pedal to rev the engine i can feel a weird vibration feeling in my gas pedal and steering wheel. Its like my engine is running rough but it sounds fine. My car was running great the day before but all of a sudden this started. Any ideas what this could be. I though that it might be a bad spark plug causing the engine to misfire which in turn causes the vibration. Any other thoughts?
Thank you,
Thank you,
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
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Could be lots of things. What happens when you drive it? how about rev it in neutral? Any more information you could possibly add?
Burning Brakes
Joined: Jun 2019
Posts: 1,208
Likes: 930
From: Georgetown, Tx
You say there is a vibration and the engine ‘sounds fine’. So I take that to understand there are no new or strange noises attributed with the vibration?
I have had belts that became bad and began breaking apart. This caused vibration but no squeal. I have also had a motor mount go bad, and pushed engine vibration into the frame. The engine mount job is the diminish a lot engine vibration.
More information would be helpful.
I have had belts that became bad and began breaking apart. This caused vibration but no squeal. I have also had a motor mount go bad, and pushed engine vibration into the frame. The engine mount job is the diminish a lot engine vibration.
More information would be helpful.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
Check the condition of the engine motor mounts and the transmission mount. If they are old, the rubber is likely disintegrating and may be weak/gummy or broken. This will cause the engine to 'wiggle around' some and give you random vibration issues. If you have one or more broken mounts, there is risk that the radiator fan COULD 'walk' into the radiator and destroy it, should you require instant WOT or heavy braking. So check it out before any damage is done. You can use pry bars and wood blocks to see if there is excess movement or if you can see separation in the mount rubbers. If the motor mounts are good, the trans mount could cause such vibrations, but you wouldn't need to worry about fan-to-radiator damage.
Thread Starter
6th Gear
Joined: Jun 2021
Posts: 6
Likes: 2
Thanks all for the assistance. My engine was completely rebuilt. Has a new top end kit from Edlebrock. Also a new Edlebrock carb. I just replaced the plugs 4 months ago. All spark plug cables are new but I did notice that one of the cables has a nick in the outer jacket. I will replace that one. I’ll check the motor mounts today and see if any of the bolts are coming loose but the mounts are also new. The vibration occurs in all gears with I including neutral. Belts are also all new.
Dr. Detroit
Joined: Mar 2012
Posts: 10,090
Likes: 4,015
From: New Braunfels Texas
Thanks all for the assistance. My engine was completely rebuilt. Has a new top end kit from Edlebrock. Also a new Edlebrock carb. I just replaced the plugs 4 months ago. All spark plug cables are new but I did notice that one of the cables has a nick in the outer jacket. I will replace that one. I’ll check the motor mounts today and see if any of the bolts are coming loose but the mounts are also new. The vibration occurs in all gears with I including neutral. Belts are also all new.
Go around at idle and start pulling plug wires one at a time......if you get a wire that when pulled does not cause the idle to drop some.....you found your miss. Replace that wire, plug...check cap terminal, etc......
Jebby
