took my 8 out for a spin Friday night and i had the sunroof open. i was doing about 50-55MPH just cruising not pushing it and i noticed a slight thumping sound. at first i thought it was another car but as i slowed down for a light with no other cars around the sound got slower in proportion to the speed i was driving. it almost sounded like when a tire starts to go flat and you keep driving on it. of course i had no flats. any body else notice this sound or have any ideas what it might be?

 

Check your lugs?

 

good idea. i'll check them tonight. the dealer had looked into a brake squeal i was having so maybe they didnt tighten the lugs enough.

 

did they fix your brake noise?

 

Has the car been sitting a while, resulting in temporarily flat-spotting the tires? This usually happens when its cold though.

 

yes. they resurfaced the rotors and put new pads on. at first it squealed worse than before but a few weeks later it's fine.

 

has not been sitting. it's my daily driver.

 

My tires make this noise after the car has been setting for just a few hours. It goes away after a few miles of driving. I'm pretty sure its from temporary flat spots on the tires. I also know of other people/cars that experience the same issue.

 

Anytime the outside air temp is below 55 overnight, my tires get a flat spot. When I go to work in the morning, I immediately enter the highway going 70. The flat spots on my tires cause the steering wheel to vibrate for 5-7 miles before it goes away. If I had the window open, I would bet I'd hear a whump-whump noise. My guess is that you're experiencing the same thing.

It's possible I'm wrong but it's the only explanation that seems to make sense so far. I'm glad this forum exists else I would have complained to the dealer and looked pretty foolish. I've never had tires this soft before.

 

I have experienced flat-spotting, too. After sitting for a few days, I notice the thump-thumping noise at highway speeds. Like others posting here, the noise and vibration in my car go away after a few miles. Perhaps this is a characteristic of low-profile tires? The tires on my Protege ES (which has 55-series tires) do not flat-spot.

 

I haven't liked the Bridgestones since the day I bought the car. I can't wait until they are worn down so I can replace them with a set of Goodrich KDW's.

Charles

 

You also might want to check the air pressure in your tires. The past few days, I noticed my tires making more noise (sort of growl as they rolled). The weather has warmed up around here so last night I checked my air pressure (after letting them cool down for a few hours). Each tire was running at about 37psi. I was surprised that the TPMS didn't light up. Anyhow, I let air out to around 32-33psi. They are quieter now.