Ever since I have had my roadster (2-1/2 years) I have noticed a very slight but noticeable vibration felt through the steering wheel which lasts for about a mile at the most and then goes away. It will not manifest itself again until the car has sat in the garage overnight. Actually the feeling is more like a washboard effect than a vibration.

Road is blacktop. New tires, balance and alignment 2K ago. Car has 18K on the clock. My mechanic has gone through the whole suspension and found zip. He says everything is tight and in good shape. That includes the brakes and bearings. Says the car is brand new.

My guess. It is the tires. It dd it before with the old ones. I believe after sitting a day or two, the tires get a slight flat spot which take a 1/2 mile to a mile to get perfectly round again. I may be grasping at straws here but we are plumb out of ideas.

Anyone?

 

It does sound like it's the tires getting flat spots from sitting if it goes away after a short drive.

 

My car used to do this inconsistently and on a rare occasion. I used to think it was tires until it stopped after I had a Speedriven SRT6 Transmission TCM tune. This winter I stored my car for six months without moving it and took it out the first day and no vibration with the same tires that I've had for two years.

 

I have a similar vibration on the roadster, which is a stick. General tires.

I do not feel it on the SRT coupe, which is auto, but on Hancooks.

 

Well there goes my theory.......

 

No matter, here are some good vibrations from a while back.
http://www.dailymotion.com/video/xxjqi_the-beach-boys-good-vibrations_music#.UYcdzcr96FU