Hello fellow Jack Daniels patron. Let me know what they say. I took mine there for exactly the same reason. They explained that it was becuase of the 20" tires. I must say I did not believe them - though I am sure they were not lying. My response was that my 20K Subaru does not make that kind of racket or bumping. They did not look happy to hear that. Oh well. Does your car rattle becuase of the unbelievably bad roads around here. They have fixed it 3 times. Each time it is better. But still not perfect.

 

My 997c4 will make this noise under braking going over a very bumpy road. Happens only at low speeds. It feels like/sounds like the abs is kicking in

 

Was at the NY Auto Show and spoke with a Pirelli rep about this issue. He put me in touch with Gary Bennard the Quality Manager at Pirelli..I spoke with him this morning and he said that it is not normal, that at low speed the tires should not skip and he mentioned that it may be the suspension (otherwise, not my product!)...he suggested that we go to the dealer and insist that the dealer call Pirelli on their hotline 1-800-Pirelli if they see an issue.

 

I'm so happy I stumbled across this thread. I was meaning to start a new one complaining about this exact problem. When the wheels are turned sharply to either side, there is an unnormal sounding resistance and it can even be felt in the steering wheel. At first I though that the guys who powdercoated my wheels mistakenly put the rears on the fronts. If others are having this problem then I feel a bit more relieved but it still is unacceptable to feel that on a $100k car.

 

Frankly, I was not completely happy with the Pirelli answer. It's there freaking tire and he did a "pass off" to the dealer...... I contacted the manufacturer and it's their warranty to me that is at issue.

May I suggest that everybody who has had a tire issue with PZeros ..give him a call and/or drop him an email?

Ok, here goes...the contact is Gary Bennard, Pirelli Quality Manager

1-203-927-0787
gary.gennard@pirelli.com

 

I think this is not about the brand or the 20" size

I had this noise always especially during cold weather
both when I had a 997.2 with 19" Ps2's

and till last week with the CS4 991 20" Pirelli's as well.

It really felt like 'skipping' indeed and I suspect the geometry of the really wide tires and large size (radius) maybe a factor...Nevertheless it shouldn't be an important issue.

 

It is normal according to Porsche. It feels like the geometry changes when the wheel is turned hard left or right like the wheels aren't aimed the exact same direction. The dealer said they all do it and I experienced it on a different 911 including my 13 Boxter S and 991S. They said it was the tires but it feels more like the geometry.

 

Didn't happen with the 19 inch Sottozero II winter tires...put the summer 20 inch Pzeros back on and bingo, it's back.

Well, ok, but it should not happen. We did not purchase Yugos and if this is a systemic Porsche 991 or 997.2 issue there should be a notice in the Porsche literature - a warning or explanation - that this may occur.

I do not like being placed between two manufacturers pointing fingers at each other. If it's harmless I want them to both make such a representation.

Maybe it's because I've practiced law for over 33 years, but I've seen this type behavior before, it usually happens when each side has no clue as to the source of the problem and no understanding as to how to resolve it and I don't like when they do it. As consumers we are entitled to the benefit of their expertise and evaluation - Pirelli put the tires into the "stream of commerce" and Porsche selected and actually certified the tires as appropriate for the 991. These guys have to get together and resolve this issue. If they say it's ok, that is fine with me...i would just like to get a definitive answer.

 

Same thing for me with both 991's. No clunking noise and only happening when turning wheels completely to the right or left when parking the car. Seems to be 100% due to the geometry and has no consequences when actually driving the car. Does not bother me.

 

When I took delivery my sales rep advised the chatter will happen with the Summer tires (20") are turned hard over when cold (he said below 40' F) and so they do. It's a an issue with the tire compound and the tire being below operating normal level. Only does it first thing on cold morning when I back out of driveway. Once temp up then no issue.

The Pirelli's for the 20" 991 application are/were a special make/design/model (or whatever) for the 991 so that's why other tires don't have the problem. It's particular to the 20" for the 991

John in Vancouver

 

Mine does it at 90F. and did it all last summer ...Dealers' admissions aside, Porschehas to admit it - they designed it, they certified it and I trust their engineers to make the appropriate pronouncement along with Pirelli.

Dealers are independent of Porsche, they do not manufacture and engineer.

 

Once the temp is up (warm morning for example) no chatter. Similarly when tires warmed up from driving no chatter on my 991S.

John in Vancouver

 

I still say that this noise and sensation is the ABS ratcheting.

Under cold/cool conditions the tires do not grip as easily and becasue of the severe turning angle, the tires start to skid. The ABS system senses a skid (even though you are only traveling 1 MPH) and starts to ratchet the on/off braking that is primarily intended to allow steering the vehicle when in a dangerous skid.


I think it's that simple.

 

Sounds reasonable to me.

John in Vancouver

 

Yep, it's the geometry. Same issue with the C6 Corvette. When you have cold tires or on surfaces that are not particularly grippy it will happen. New tires with soft rubber and good tread might avoid it for a while.

But the ABS could be contributing to it and we should try turning the ABS off to see if it remains the same.

ChuckJ