cars shaking on acceleration?

**vinnY** · 05-09-2008 12:10 AM

i've had the problem for a couple months now but i've sorta just ignored it
seeing as it's spring now and not freezing enough to stop me working outside i thought i'd try to track down the problem

so the problem is in a certain rev range in certain gears, the car will just shake upon acceleration
minor vibrate in the steering wheel
door trims shake and rattle
side and rear view mirrors tremble to the point where you can only make out a blur
misc bits of trim and loose change rattles in the car

generally felt between 2200-3200rpm in second and third and sometimes fourth gear. so usually at rather low speeds i.e. 30-70km/h
backoff the throttle and the violent shaking seems to stop momentarily
sometimes happens in fifth gear on the freeway around the 100-120km/h mark
give it some throttle and it shakes, ease off the throttle and it shakes but not so much

bushes seem to be ok(although will be changing soon)
no cv joints are busted
all bolts are tight
suspension is all seated properly and nothing out of the ordinary

i had a theory that it might be a ignition issue i.e. motor is firing funny at the given rpm range and causing excess vibrations that transfer into the chassis(have solid rear and torque engine mounts)

anyone else want to offer suggestions to my problem? would be much appreciated

**VTECMACHINE** · 05-09-2008 12:32 AM

Wheels weights could have fallen off, and wheels are no longer balenced. Could explain some of the problems above...

My 2c

**lam.666** · 05-09-2008 01:15 AM

i believe stock rims wouldn't do that, possibility of after-market "lighter" rims results to shaking whilst revving at low range?

**vinnY** · 05-09-2008 01:18 AM

forgot to mention running stock ek4 rims
looks like wheel weights are still attached, might just have to get them rebalanced again

will try this weekend and see how i go

**CB7_OWNER** · 05-09-2008 09:49 AM

engine mounts..

**g_kn** · 05-09-2008 11:03 AM

prolly the Wheel Balancing weights came off one of the wheels , if not check for any signs of a slight dint on one of the Rims/wheels.

**02gzm** · 05-09-2008 11:40 AM

Originally Posted by CB7_OWNER

engine mounts..

x2

If it is a vibration and not a miss and it only does it when you have ur foot on the gas, i.e. putting load on the engine, then it's gotta be one of the mounts. It's probably only minor so it'ss only doing it at certain frequencies of vibration, like at the RPM range you said. But you'd wanna get it checked out and fixed asap

**Limbo** · 05-09-2008 11:41 AM

nope light rims do not result in more shaking.

I'd say either rims need balancing or your solid mounts are increasing vibrations

Originally Posted by lam.666

i believe stock rims wouldn't do that, possibility of after-market "lighter" rims results to shaking whilst revving at low range?

**vinnY** · 05-09-2008 12:18 PM

engine mounts look okay
i don't mind the idle vibration but the whole car shaking on acceleration, i'm a bit iffy about

will give balancing the wheels a go and see if that helps being the cheapest/easiest thing to do right now