I have recently purchased a 2000 Bonneville SLE with 85k miles. It runs smooth normally but when I put it in reverse to back out of my garage the engine seems to transmit a lot of vibration through the chassis. For example the dash rattles internally and the steering wheel seems to vibrate - it just seems harsh. My 2000 Grand Prix does not do this. Could there be motor or transmission mounts that fail over time resulting in the engine or drive train grounding to the chassis under certain load conditions? Any other things to check?
2000 Bonneville engine vibration
Mar 03, 2007
3 Replies
You need to put it up on a hoist, power brake it in reverse and look for the ground out.
Also watch the mounts for excessive movement.
Good idea - wish I had a hoist. Is it typical for motor mounts to fail at only 85k miles?
That does seem quite early to go bad. I would guess something in the line of a bent exhaust or missing exhaust hangers. Look for after market parts installed wrong.
Instead of a hoist, put it up on ramps and go under. Then have someone you trust power brake it. Watch you don't burn your nose. Most of the time it's the exhaust hitting a heat shield or the down pipe making contact with the tunnel.
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