keithwatson

Today I drove my 07 C2S for the first time in a week due to inclimate weather. Well, the weather actually was still inclimate today as I drove down one mostly snow covered road for about a mile. The temperature was 2 degrees. I got on the interstate, and as I approached 55 mph, I noticed the steering wheel jerking somewhat violently. Naturally, I thought of tire pressures, though TPMS showed the right front at 30 and the right left at 29, both rears at 35. No warning was shown. So I continued at about 50 mph. I went to work and just came back and it is still doing the exact same thing. I got new tires about two months ago. Why was my car driving fine a week ago and now it's not?

irish guitar

It could be that the tyres have flat spots from being parked up. Has your car sat this long before?

jumper5836

ice or snow in the wheel can make them unbalanced

Likemystoppie?

Could it possibly be you're drunk?

Just ask'n!

gota911

Probably due to flat spotting, which will normally go away after you have driven a few miles and the tires warm up. However, since you were driving in 2 degree temps and the tires did not warm up sufficiently to eliminate the flat spots.

ELUSIVE

Which tires do you have?
My Pirelli Pzero's flatspot a TON more than my Michelin's did. No more Pirelli's for me!
I bought some TireCradles and they still flatspot some but not nearly as bad.

cviles

Three things come to mind:

Flat spotted tires -- if you're on high performance tires, they're like rocks in the cold weather and after sitting so long and will produce a vibration in the wheel for a while, but it should go away.

You picked up some snow -- this is more likely as you describe your vibration as "violent". Check the tires for debris.

You threw a weight -- one or more weights have become unstuck and dropped off the rim. You can eyeball each wheel and see if at least some weights are still on the rims or you can just have them rebalanced and see if that fixes the problem.

keithwatson

Thanks for the insight. And I was only mildly drunk--just kidding. I think I will assume I picked up snow and/or flat spotting for now. There was definitely snow in the rims when I checked after work. No my car has never sat this long so it may very well be flat spotting. I switched out continentals for bridgestones to get a little more life---I had to replace the rear conti's at 7500 miles and porsche actually bought my new fronts.

BobbyB

I wouldn't think flat spotting in just a week. My car sits for 3 or 4 weeks during the winter with no problem. What type of tires do you have? -at only 2 deg F. rubber can make a difference. How were the roads, clear, smooth or covered with patches or ice/snow?

Crazy Canuck

I've had that happen a few times.

mb1

I made the mistake of not cleaning off the wheels after this adventure. The car shook badly above 40 MPH but was fine after I cleaned off the snow.

cole328

Move to florida....!! I can't imagine having a porsche have to sit for 4 weeks due to weather issues...-(

mdrums

Doubt it is flat spotting the tires. I bet a wheel weight fell off. If the tires are flat spotting you will feel it at all speeds.

richc

tires shouldn't flat spot in a week - i;ve left mine parked for months and never had a problem. my guess is ice/snow on the wheel.

RonCT

Not flat spotting - if you left the car for say 6 months and had flat spotting you'd get a slight vibration. Violent shaking is snow / ice build up -- seriously imbalanced wheels. I've had that happen with a variety of my winter cars and simply pulled over, cleaned them out, and back to normal. Don't bother with things like Tire Cradles - all you have to do is every 2 weeks run the car to keep the fluids moving and seals lubricated and roll the car 3-6" to prevent flat spotting.