eweidnerblue

When the car is revved at 1600-1900 rpm, it vibrates - whether I'm stationary or moving. Has anyone found a permanent fix to this?

My dealer/service dept. fixed it once, but it came back after 6 months or so, and they weren't certain what they did to fix it - it just went away.

Ideas? Thanks!

carbonLORD

All cars vibrate at idle when you rev the engine.

SloopJohnB

or something like that.
What did the dealer do the first time they 'fixed' it?
Perhaps it's one or more engine mounts. They're only good for so long anyway and then there are random failures.
Vibrations are always caused by something out of balance, some unbalances are left that way by design or are impossible to correct/design out, therefore hydraulic or tuneable engine mounts.
??

Eric 2.7

I had a very similar thing with my 1996 B5 A4 (2.8 - 12 valve). It was at a very tight place in the revs (+/- 100 rpm) just under 2000 rpm. It was not a serious vibration, but it was enough to notice if you stayed at that RPM. Inexplicably, the vibe was worse the colder the outside temperature was. I finally gave up trying to find the source and figured it was just the rotating mass hitting the natural frequency of something else and not a major problem. Sold the car to a buddy with 105,000 mi and he has something like 130,000 on it now with no ill effects related to this vibe. Don't know whether this has anything to do with a C5 4.2 vibration, but the symptoms sounded similar.

eweidnerblue

I first noticed the vibration when I was moving @ around 45-50 mph. The dealer said it was tires, balance, etc. So, he balanced the wheels and the vibration remained. For some reason, I thought it wasn't the wheels, so I tested it while not moving. The vibration happens when I'm moving and not moving - so it obviously isn't related to the tires or wheels.

eweidnerblue

jhuston4, SloopJohnB & carbonLORD - thanks for your emails and thoughts. Solutions so far:
- I'd rather not sell the car just yet - it only has around 30k miles, and my wife loves it . . .
- I'm going to take it back to the repair shop and see if they "accidentally" fix it again!
Thanks again and wish me luck!

April

advance (the solonoid and gear that should switch on around 3200rpms) and the intake runner switchover gear (it's too low for it to change over to shorter runners, but maybe it's doing a partial opening).