Vibration at 80+ mph

[triumphbc]

When exceeding 80 mph the front of my car has a terrible vibration which makes highway driving really irritating. I have been dealing with the problem for a while, but just can't seem to find the cause and thought someone here might be able to help. Here's what I know/have tried:

- Rims not bent
- new front tires, balanced
- new control arm bushings (offset urethane)

The previous owner had also recently replaced the ball joints, and I think the shocks (though they look to be in decent order anyway). The shop I take it to doesn't see anything glaring, but they won't drive it at the speed where the problem occurs. Right now I've been guessing and replacing older suspect pieces (bushings, tires), but that isn't cheap and so far I have been wrong. Any suggestions?

 

[Tom]

Try moving the rear tires to the front to see if the vibration goes away. If you have bad tires, balancing them will still not help.

 

[triumphbc]

The front tires are brand new and naturally where balanced when I bought them.

 

[rjp325i]

Move the rears to the front and try it as Tom says. Eliminate the question of wheel/tires. If it goes away, double check balance, it would not be the first time a wheel tossed a balancing weight after being balanced. Or the tire may be out of round if the problem goes away after switching. Next if the vibration occurs on uneven pavement it is a good possibility the front struts need replacing. When were the struts replaced? Check the ball joints, there should not be any noticable play.

 

[Wadula]

i had my tires balanced just recently and immediatly after i left the shop the vibration started. as with you at about 75 and plus. i think that the balancing is onky done to speeds that do not exceed the average speedlimit of 65-70 mph...

 

[JTM]

wadula has prolyl got it righton the $$, when they balance tires they only do it to about 80mph. if you exceed it.. theres no guarantee. also make sure your tires are rated for those types of speeds.. blowouts suck

 

[bignate]

You might need a front wheel bearing repack. Its a fairly simple job and costs virtually nothing if you have a grease gun.

 

[mikev]

this sounds like the common problem most euro drivers face (not being mean but we drive at higher speeds) in my E30 and dads E34 M5 there is a vibration at between 80 - 100Mph but it disappears above this. all it is (i think) is the brake disc being ever so slightly warped and rubbing causing the vibration (it can be so minute that it falls out side of most tests at local dealers) its not a huge issue for me as it disappears (this has happened to several people i know) I would get it fixed but i've got so used to it that i don't even think about it and its also a nice reminder that i'm about to enter the license loosing area (90+)

 

[Wadula]

mike, i think even that vibration ist the tires. the weights multiply their weight the more the revinng of the wheel is. a two gramm weight easily gets to 20 KG. always when a vibration comes and goes it is matter resonance frequency and forces. a brake pad or disk will not vibrate at certain speeds only.

 

[mikev]

true, that makes alot more sense than what i was told before

 

[M-Punk]

You have to check your front discs. They are almost certainly warped. It is a well known 325i problem.