Vibration in steering only on Warm Days - 986 Forum - The Community for Porsche Boxster & Cayman Owners

m208334 · 04-07-2010, 05:19 PM

1999 Boxster - I have a problem that has been driving me nuts for three years. Every summer, when the outside air temperature rises above 80 degrees, I feel a knock/vibration in the steering wheel that appears to be coming from the front driver side wheel.

I only notice the vibration at very low speed (10-20mph). On very warm days, the vibration occurs pulling out of the parking lot on the way home from work. On 80 degree days, the vibration may not occur until I get off the highway and slow down.

I have replaced the front struts and steering rack. Before I replaced the struts, if I pushed down on the driver side strut on a warm day immediately after driving, the suspension squeaked. However, if I waited 2 minutes no squeak. With the new struts, the suspension is too stiff to squeak. Tires and alignment have been checked. I have not replaced any control arms or wheel bearings. Car has about 45K miles.

The problem never occurs on a cold day no matter how long I drive.

I am the original owner and the car is maintained regularly by a local shop (http://www.autosofeurope.com/). The car has never been in an accident. Any idea what might be causing this temperature related suspension problem?

Steve Tinker · 04-07-2010, 10:41 PM

Boxsters are very sensitive to wheel balance - mine used to vibrate when the tyre was cold. I would suspect a faulty tyre or wheel - you say they have been checked, but an out of round tyre is hard to detect unless on a good balancer (Hunter?).
For a quick confirmation, replace the front wheel with your spare - at least that way you can isolate which wheel/tyre combo that is giving you the problem....

m208334 · 04-09-2010, 12:35 PM

Thanks! I will try replacing the tire. It just seems odd that outside temperature would affect a tire.

jcb986 · 04-09-2010, 01:08 PM

I live in Florida...during our cold season I get a little wobble in the first 25 miles, then everything is fine. During summer season I do not have any kind of wobble on the get go. You also could have lost a small weight since they are peel n stick types.

m208334 · 04-21-2010, 03:13 PM

Tires were not the problem. Front passenger side tire still vibrates when hot at low speeds (5-20mph). Now the front brake seems to have a loud metallic squeal that only occurs only when the car is hot. Brakes are only 6 months old. Brakes are always quiet on cool days (<75 degrees).

Obviously something is going in the front. Any ideas how to troubleshoot? I may need to take it to the mechanic when it is hot.

eightsandaces · 04-21-2010, 03:44 PM

Quote:

Originally Posted by m208334

Tires were not the problem. Front passenger side tire still vibrates when hot at low speeds (5-20mph). Now the front brake seems to have a loud metallic squeal that only occurs only when the car is hot. Brakes are only 6 months old. Brakes are always quiet on cool days (<75 degrees).

Obviously something is going in the front. Any ideas how to troubleshoot? I may need to take it to the mechanic when it is hot.

The best way to troubleshoot it IMO is to pull the wheel and locate the noise. The age of the brakes doesn't necessarily mean they didn't fail, check the rotor face for a smooth clean track. When you jack it up, spin the wheel manually, that may give you a clue as well.

jcb986 · 04-21-2010, 03:59 PM

Quote:

"Tires were not the problem. Front passenger side tire still vibrates when hot at low speeds (5-20mph). Now the front brake seems to have a loud metallic squeal that only occurs only when the car is hot. Brakes are only 6 months old. Brakes are always quiet on cool days (<75 degrees).

Obviously something is going in the front. Any ideas how to troubleshoot? I may need to take it to the mechanic when it is hot."

Originally Posted by m208334

Tires are subject to going bad...the belts can begin to separate and you will need see it. One way to trouble shoot it is to swap tires and see if the problem moves to the other wheel. As for the squeal, I would think something like a wheel bearing going bad but if the squeal only happens when compress the brakes, it most likely the pads. Cheap metallic pads are to me a no no...they will feel good but once they start to wear you can get a squeal. Good pads on a Porsche are semi-metallic compound, yes , more dust.

m208334 · 04-21-2010, 06:02 PM

Thanks. I will look at the brakes, but as I said, The squeal only occurs on hot days. I hear the squeal when I slowly creep over the curb as I exit the drive (downhill) or as I slow going downhill. Could bad bearings cause the temperature related wobble? That is something I did not consider.

RandallNeighbour · 04-21-2010, 06:48 PM

The creaking when you go over humps or bumps is probably your control arm ball joint going out... mine have gone out repeatedly. Only happened to me after it rained and I had the car out in very humid summer weather. Go figure.

The low speed vibration could certainly be a wheel bearing. Checking isn't hard... jack it up and spin that wheel real fast and listen for noise or grinding. Then grab the top of the tire and yank and push in and out toward the inside of the car and see if there's any play in the bearing.

If you can locate another box owner in your neck of the woods in your PCA region, ask them if you can "borrow" their front rims for a half hour and put their tires and rims on your car and drive it around to rule out the front wheels and tires.

m208334 · 04-30-2010, 06:28 PM

Thanks JBD986 & Randall!

The wheel bearing appears to be the problem. I may have wasted some money chasing this if the bearings fix the problem.

I am getting a second opinion Monday and will post if the wheel bearings fix the problem.

Glass · 05-23-2010, 01:14 PM

What did you fing it to be?

I have the same problem on my 99 with 46000 miles. When I lift the car and push the tire in and out on the top is has a very slight clunk you can feel in your hand. I think its the lower control arm ball joint as I pulled the wheel and found no play in the bearing.

m208334 · 05-23-2010, 04:59 PM

The bearings checked fine. I am waiting for another warm day to diagnosis the problem. I have about 36K on the car. This is only the second set of tires I have had on the car, so it is still possible that I have a bad or flat-spott

ed tire. 5 year old tires should be replaced, but I wanted to fix the suspension problem first.

Let me know what you find.

Glass · 05-25-2010, 12:24 PM

I replaced the sway bar bushings... not it. I repleaced the sway bar end links...not it. I replaced the lower control arm...not it. Now I still have a very slight clunk when pushing the wheel on top towards the inside of the car, so the only thing left is that wheel bearing. It appears that the slight play transmitts trough the steering feeling like a clunk. I have the bearing on order and it looks like a pain to change.

RandallNeighbour · 05-25-2010, 01:09 PM

I have the bearing on order and it looks like a pain to change.

That would be an understatement. It takes specialized equipment too... the part is cheap but the labor involved is something like 3 hours per bearing.

ijwalsh · 10-13-2010, 03:27 AM

Did you ever get to the bottom of the problem? I have the exact same knocking through the steering wheel slow speeds after driving a while to get everything warmed up...

JDBOXSTER · 10-13-2010, 03:56 PM

I went thru the process of elimination and replaced the shocks.strut bearings drop links and outer track rods. No change in knocking, still only after the front end gets warm.
Changed the inner track rods and "Bingo" problem solved.
Hope you have the same situation.

JD BOXSTER