JG26_Irish

I have a question: Are Pirelli P-Zero Nero tires all pieces of sh@# ?? or do I just have a bad impression of them? Plese let me explain.

2003 C32 AMG with stock 17" rims shod with new Pirellis. I go out to push the car in the corners auto-x style. Low speed hard left right transitions, etc. All of a sudden, Pssssssst, the left front deflates completely all at once. WTF? Thorough check reveils no damage to tire or rim and 5k miles later it has never done it again.

Now to the rear. Twice in the last 3 months, the left rear has deflated to zero psi for no obvious reason. Both times I was out for short errands, both times on the way home, I turned off ESP and hammered it hard in 1st and 2nd. Both times, I noticed no change in the car, the handling or tires, but it was dark. Both times, the next morning my left rear tire was totally flat. Zero PSI. Both times, I pumped it up and both times it held air. I have had the rim with the tire mounted dipped in a bubble tank, and broken down to see if the rim was corroded inside. We can find no sign of anything wrong with the tire or rim.

I am starting to get paranoid that I have a prankster in my neighborhood but lets face it they would be more random and usually are too lazy to get out in the cold weather to F### with somebody's car. And I live in a near zero crime area where you literally can leave the keys in your car and nobody messes with it. So, I am doubting the prankster theory. Any ideas? Anybody else having trouble with Pirelli tires holding air randomly?

Irish

F1Bobby

JG I have those tires on my Lex IS300. I push the Sh!* out of them in the Canyons. I have never had an issue with them at all. This is the 3rd set on the IS. I'm wondering what the hell happened to you... Whatever it is wasn't good. If you're peeling them off the bead because of the excessive load in cornering then any tire will come of the bead that way. I guess I told you all this to simply say all the P-Zero Neros that I've had have never done what's happening to you. My C55 currently has Dunlops so I can't give you an answer based on car weight etc...

DarkXerox

No problems with mine

willc55

I read somewhere that this can happen if the tire spins on the wheel, which could explain the rear more easily than the front. As for the cause, I don't know but maybe if you know the cause you can find the solution.

JG26_Irish

The rim slipping or spinning in the tire is exactly what I thought was happening with the rears. Normally with ESP off, the right rear will spin more but the left will try to spin and then grab and if the Pirelli bead is not tight it might be slipping on the rim allowing a loss of air pressure. I have never had a performance tire do this ever, but then the C32 with the pulley kit makes a ton of torque but then so do alot of AMG's. I am sure that I am not the 1st AMG owner to go out and gas it hard from a dig.

In the last few weeks I have been doing tuning on this car which involved dozens of pulls from 0-60, and faster. Not once did the tires give a problem. The car was always in the driveway when the flats occured.

I ran it at the track dragstrip) where if anything the chance of doing this us far greater due to the very grippy burnout area and the very good traction off the line. No issues at all at the track. Both times this happened, I got on it hard a little and then backed off. It could be the sudden regaining of traction allowing the tire to slip. They were pumped up to between 35-40psi and thus this should not be happening. I'm just wondering if others have seen this???

I usually ran Bridgestones. This is my first and likely last set of Pirellis.

Irish

JG26_Irish

Here is the latest. I checked tire pressure on the rear to be 40 psi. I then went out today in the daylight and conducted as close of a repeat of my past actions as possible including a couple of romps on it with ESP turned off. Nothing massive or even bawdy enough to be noticed by the local constables. I just spun it up a little, let off and let it catch traction suddenly. I also marked the tire at the valve stem as a reference if the rim was slipping.

When I rtb'ed the tire inflation looked normal. If the rim slipped any at all it was a undecernable amount. Two hours later, I went out to check on the car and the same left rear was nearly flat. Down to 10 psi. I pumped it back up to 40 and as of now it is still inflated. I am baffled.

Irish

willc55

Now I'm totally just guessing, but could there be a hole or crack in the tire that doesn't manifest itself when the tire is cold, but when it heats up past a certain point and the rubber expands lets air out?

Probably talking nonsense, but just throwing out what came off the top of my head.

MRAMG1

Well let's just say I have NO lover for my EX Pierelle's

Pics say a thosuand words:






See yeah

SilverBulletAMG

This was my first thought. Heat makes the most sense here. Tires were hot in the front when it went flat and same for the rear. Both tires that deflated are on the left side and both went flat when the tires were very heated. Leads me to believe it's related and you have a seal breaking when the tires get hot. Still screwy but it fits the symptoms.
Are the tires still under "warranty"? How many miles on the tires?

AMG Sleeper

you jack the car up and check for any bends in the rim?

JG26_Irish

Thanks for the input and suggestions. Regarding the condition of the rims. I have had both the front and rear off the car, visually inspected, dipped in a tank of soapy water to look for leaks in tire or rim. Even broke the tire down to inspect the inside of the rim. No punctures and no bubbles and no bent, cracked or damaged rims.

As for the suggestion that heat is the culprit. That is doubtful. Sure they are warm after driving a little but hardly hot. The ambient temps have been below freezing here for months and in every case this occured after short trips where speeds were slow and very little heat was getting into the tires.

I did fix the problem yesterday. The solution? Bridgestone

Upon close inspection of the rear Pirelli, I did see a tiny puncture in the center of the tread that was not visible before. No air leaking out and no foreign bodies in the tire. Still that could be just deep enough to allow air out intermittantly, I suppose. If anybody wants a nice set of Pirelli P-Zero NERO's for the front, they are 50% worn but the price is right. Cheap.

MRAMG1

[QUOTE=JG26_Irish;3364332]I did fix the problem yesterday. The solution? Bridgestone

QUOTE]

That what I did my friend

See yeah