Bad steering wheel vibration.

[E30Rookie37]

When I originally purchased this car in December there was noticeable vibration through the steering wheel but not terrible. After some driving the vibration has just gotten worse and worse to the point where the dashboard even shakes sometimes. It occurs at pretty well all speeds but no vibration when the car is stopped so it has to be something with the steering I think, I just don't know exactly what. It probably needs an alignment and balance but I don't think that would cause the vibration and generally my car will drive pretty darn straight with my hands off the wheel. I bought a used steering rack that's in pretty good condition but I've yet to replace it because I really don't know if it's truly the issue or if it could be a tie rod or something the like.

I guess my question is how can I narrow down what the true underlying issue is since it could be quite a few things? Or what's the most likely cause of the vibration.

I'm new to this board and to BMW's and E30's so any help is much appreciated and if this question has been asked and answered elsewhere could someone direct me to the thread.

[jlevie]

The first thing to do is to have a pro inspect the suspension. A pro can tell you what parts are worn and need to be replaced. On an E30 with a good bit of mileage on it that will probably be control arms, control arm bushings, tie rods, struts, and upper strut bearings. But the car could also have bad wheel bearings. Unless it is leaking, the rack is unlikely to need to be replaced.

When the worn parts have been replaced, have an alignment shop set the front toe and balance the tires to complete the fix.

Having said that, the probable causes of what you are experiencing is most likely due to a combination of misalignment, out of balance or bent wheels, and worn out struts.

[Ceeker]

like he said. best to get it in a shop to check everything over - unless you know how too!

[Dolmangar]

Check tire pressure first. Don't eye ball it. Get a good gauge and verify that it's to the spec listed in the door jam. If you're 10 PSI off side to side you can have lots of problems.

While you're at it verify that the lugs are tight, and that you've actually got a set of tire and wheels that match.

Most likely this ISN'T the issue, but might as well check the free things first before you start spending money.

[nomansland92]

oh boy gotta love chasing vibrations haha but jack the front of the car up and start check everything
with tires off the ground

Wheel bearings
grab tire at around 9 and 3 o'clock and moving in and out check movement

checking ball joints
grab the tire top and bottom and try to move wiggle it and feel for movement

even slightly off balance tires can cause vibrations however using alignment usually doesn't

check all the bushing and any moving parts obviously

does the vibration get better or worse when hitting the brakes? possibly warps rotors as well
Go through and check all the bolts like a arms, tie rods, suspension etc.

hope this helps