CAA

Looking for some advice here. About a month ago I moticed that my steering wheel developed a relatively violent shaking at around 50-60 MPH. I was told that I needed my wheels balanced. I took the car in and had this done. After I picked it up nothing had changed. I returned the car to be fixed again. It is still the same. I was told that there is a flat spot in one of the tires from not "driving the car enough" and that it's being caused by a flat spot on one of the tires. Is this even possible? These are Pzero's on a C4S with less than 5,000 miles on them. Installed in March of this year....any advice or similar situations? Thanks.

Mr Michael B

"Is this even possible?.."

Yes of course it is.

You can find small rubber pads to park on (that will help). "tirecradle"

Any tire, no matter what brand, can "flat spot" from sitting.

However a "real" flat spot would be from skidding it along the surface and erasing the tread like a pencil eraser (not your issue).

You will be able to make your tire round again by putting in a nice long brisk drive though. Its really just an "impression" on the rubber and not worn away obviously, so drive it till you get some heat in the rubber then park it on those rubber pads. That will do it.

Gump993

Yep.. Unfortunately if you leave the car standing for a while the tire will develop flat spots.
I've been told by the tire guy that if you are gona leave the car for a while then better put some extra pressure into them.. it helps to avoid any flatspots.

Happened to my friend last week. Came back from holidays and his P Zeros where messed up.

You shouldnt leave you car sitting around anyway.
Porsche are meant to be driven!
Cheers

Nol, 95 993 C4

I don't see how you could have flatspotted just one of the tires from not driving the car? Sureley that would affect all 4 tires equally But if that is what happened, what's different about that one? Is it damaged somehow, maybe without showing on the outside? Maybe get a second opinion, did you balance the wheels at the shop that sold you the tires?

Enjoy <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Nol

CAA

Thanks for the replies. Nol, the tires were purchased at a diff location than where they were balanced. I also thought that if it were a case of flat spot it would affect all 4 tires.....

Allen

I have heard of and experienced flat spots on Pirelli Pzeros after the car has sat undriven for about 2 weeks or more. However, after driving the car for about 10 - 15 minutes or so, the flat spots go away and everything is back to normal. I can't see how just sitting can cause a permanent flat spot. The tires are rubber. They will deform if sitting long enough, but I can't believe they would stay that way...at least I've never heard of it.

N105DVV

I have had similar experience with P-zeros. The flat spots can be driven out. I binned the Pirellis soon after.

Phil...

Allen

I don't believe this "flat-spotting" is something that happens only to Pirelli Pzeros. I think it happens to all brands. Some may do it worse than others, or require a longer 'sit time' before flat spotting, but I think they all do it after sitting long enough. Now if you somehow lock up your brakes, and a tire skids for some distance...that would cause a flat spot on the tire, as the rubber is worn off of a particular spot on the tire. This is what you will see in racing.

CAA

Well, I don't really know what it is then. After the "not driving the car enough" comment I took it out for a long run and also started driving it more. Still there. I will add that on my previous 993 C4 I had Toyo Proxes and didn't have this problem. The P Zeros provide great handling in dry weather, but they seem extremely soft. Every time I wash the car I notice a good coating of worn tire on the rear inside wheel wells.....

Greg Fishman

I had two Pirelli's replaced by the dealer when my car was new. They tried to balance the tires several times to no avail. Maybe it is more than just a temporary flat spot. At the time the dealer said it wasn't uncommon.

Mark Buka

CAA:

Check your lug nut tightness. I know what you're
thinking. It happens. The fellows that mounted
your rims might have misaligned a rim by not tightening the bolts correctly. Happened to me.

hn

With my busy schedule and the kids, sometimes I parked the car for 3 weeks to a month. No problem so far on the Michelin Pilot Sx.