Vibration in steering only on Warm Days
 

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?

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....

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

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. :cheers:

Problem Getting Worse
 

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.

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. :cheers:

Brakes
 

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.

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.

Vibration on only on hot days
 

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.

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.

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

Let me know what you find.

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.

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.

Glass, Does your problem only exist on warm days?

I have not looked at the bushings on the lower control arm. I am still perplexed that the car is fine on cool days, but on warm days the driver side front suspension knocks like crazy at very low speeds (5-15mph).

yes only warm days, it gets after you drive it. It does not do it for the first 10 miles or so until things get warm.

What part of the US do you live in...State. Did you buy the car new and did you do anything or hit anything like a big pothole in a few months before your noise showed up.

"What part of the US do you live in...State. Did you buy the car new and did you do anything or hit anything like a big pothole in a few months before your noise showed up."

I live in the Missouri. I bought the car new 11 years ago for my wife (and lost my corvette), but she hardly drove the car. About 2 years ago, I finally decided to drive the car and I really enjoyed the car. However, I returned to my Acura in the summer when the car became noisy. Since my son is 15 and starting to drive, I need to have the 3rd car in working order and plan to drive the boxster as long as the weather is not icy.

Update: Yesterday, the temperature was 93 when I left work. The problem started about 10 miles later so I decided to see my mechanic. The owner rode with me in the car (Autos of Europe ) and during the ride he said the noise was metal on metal. He called this evening and said he thinks he fixed the car but is not going to charge me until I drive it for a while. He said I had some lose/broken heat shields. He also told me my suspension is perfect and bushings are good everywhere. I will let you know if this fixes the problem. I am interested to hear why he thinks the outside temperature affects the heat shield.

My Site with one radio code contribution to Porsche Boxster users (after my own frustration) and a lot of my odd java programs: A2DVoices If you ever need a quick algorithm or calculation for cars, I might be willing to donate my help.

I'm betting the heat shields expanded in the heat and that's why they started making a racket.

I've beat on my heat shields with a hammer a couple of times to get rid of annoying metal on metal sounds and rattling. Boy that felt good.

Unsolved
 

Picked up the car this afternoon. The heat shields did not fix the problem. I still feel the knocking in the driver side front at low speed.

Another member suggested the inner tie rod might be the problem. I called the mechanic before I picked up the car and asked about the inner tie rods. He said he would look. Later, he offered to change the tie rods if I wanted, but was indicating it was my decision. He still thought the heat shield fixed the problem. That is why I decided to pick up the car and give it a try. Apparently he is not hearing/feeling the knock. The tie rod job is $1100 if I decide to go that route. I would gladly pay $1100 if the problem would really be fixed. Probably time for another opinion. Not sure where to go, but I am not ready to admit defeat.

Here is a video clip of the actual sound. When the knock occurs, it can be slightly felt in the steering wheel. The knock frequency does not change with speed, but it is not felt as much at highway speeds. This video was taken after the car was driven for about 10 minutes. On another portion of the video, the car makes a horrible metal sound while turning around very slowly. The knocking noise: The Annoying Front Suspension Noise