LSneewb

Needed a spot diagnosis for my current dilemma. So whenever I drive the LS after a couple of days there is this faint persistent vibration felt in the steering wheel for the first 1-2 mins of highway driving > 60mph. It then goes away and doesnt come back until the next cold start. The car has a little over 70k miles, brand new tires and control arm bushings and is otherwise dead quiet and straight except for the first couple of minutes after it has been sitting a while. Braking does not have an effect on the vibration. Anyone else have a similar issue? What could it be?

bradland

I agree with Rex.
When it sits is it a couple days or 4 or 5 days?
If it's not tire related I'd take a look at the PS fluid, it's either low or needs replacing.

ls430w140

Chinese tires and some other ones (including Falken) are primary reasons for this condition. Also rebalancing the wheel is important to consider.

LSneewb

Thanks LexRex. You nailed it I think. My tires are Continental DWS and hardly have 2000 miles on them. It has been a little on the chillier side here and I think its the flat spotting thats causing it early in the morning. The article you linked from tirerack mentions this is a common problem on high performance higher speed rated tires. Nothing can be done about it but the warmer weather should fix it.

In answer to the other users comments...The powersteering fluid is fine and that usually causes a whine if it needs changing. Good thought though.

Thanks guys!

leisinjp

The Continental DWS are great tires. When I had my Acura TL Type S and Lexus ISF both forums always recommended those tires. The one concern I did hear often about them was that they get flat spots after sitting. I'm no mechanic but when I would leave my Michelin Super Sports on my ISF in the late fall and it was colder, the first couple minutes of my drive would be like driving on square blocks. Then they heat up and you are good.

Bocatrip

Flat spotting. I hardly drive my Jaguar as it sits sometimes for months. When I take it out on the highway I get a slight steering wheel vibration that is gone within a few minutes. No big deal.