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?