So my car vibrates a lot...

[timothy100]

I know it could be a million things, but i am by no means anywhere close to being a mechanic. I can do some basic work but nothing fancy. A friend told me I probably need new transmission mounts (after getting under my automatic 86 325e and looking at them).


Could worn transmission mounts cause some pretty serious vibration under acceleration at lower speeds? If so, how hard is this to fix? Or more realistically, how much would it COST to have fixed? Thanks...

[Bill 84 318i]

If you can safely put a car on jackstands, you can replace the transmission mounts. There are 4 (13mm?) bolts that hold them on - two each. Just remove the nuts, jack up the tranny an inch or so, pull the mounts out, and installation is the reverse of removal. Other things that can cause vibration are bent wheels, out of round tires, out of balance wheels, worn control arms, worn control arm bushings, worn tie rods, worn guibo (flex disc), driveshaft center support bearing...and the list goes on.

Can you describe the vibration? RPMs? Does the car shake, the steering wheel shake, or both? Does it only happen at certain speeds?

[timothy100]

the vibration is most intense when acclerating from a stop. after i get past 30 or so its not nearly as bad. after 40mph, theres pretty much no vibration due to acceleration. i cant really tell where its coming from... the steering wheel doesnt shake, but all of the plastic on the console rattles. there also seems to be a loss of power, like if i press on the pedal it doesnt really accelerate, if i press it down further it gives out a spurt of power. the best way i can describe it is the acceleration is just really rough. also, it seems to happen at lower rpms (below 2000 or so).

thanks for the reply

[alex]

It might be your driveshaft center bearing that's causing all that vibration.

The part itself isn't very expensive, around $25-30, but it does take a coule of hours to change.
Where are you located?

[timothy100]

renton, washington

[alex]

Just a couple of hours away... Did you locate a problem?

[86325e]

When I first got my car I had a bad vibration during acceleration and cruising on the interstate. The center bearing was the culprit of the vibration during acceleration and the tires were the cause of the vibration on the interstate (out of balence).

[timothy100]

Today I dropped my car off for a tune up. I haven't figured out what the problem is yet...

[franz]

Well, it sounds like SOMETHING a checkbook or mastercard could fix. But just curious, why ask us then?

[alex]

Well, it sounds like SOMETHING a checkbook or mastercard could fix. But just curious, why ask us then?

So that maybe next time he'll know what the problem is and will perhaps fix it himself. Or maybe he just want to sound knowledgeable when he talks to a mechanic. You get the idea. Lots of possible reasons...

[timothy100]

I asked because this is my first car. I don't know very much about cars at all so I'm trying to learn more... I want to be able to learn more so I can fix stuff by myself, but for now I dont feel comfortable doing anything too complicated. I don't have any mechanic friends so I figured I'd see what you guys think.

[modifiede30]

What happens at about 20-30 if the car is in neutral (coasting)? What about the same speed braking?

[timothy100]

coasting at that speed is fine... same with braking. no strange vibration or noises

[modifiede30]

If its shaking while accelorating, and not when coasting or breaking at the same speeds, its likely something is wrong between the tranny (if not the tranny itself), and the diff. This means that its likely the guibo, center bearing, or an output bearing. What happens if you accelorate more slowly from 4th gear all the way up?

[timothy100]

my car is an automatic, and almost all of the vibration comes from 1st gear or 2nd at low rpms