Final Update

The good: The car is repaired and back home this evening.
The bad: No clue as to why the car is eating rotors.
The ugly: Car was at dealer for 9 days.

To review, after 2 months of ownership and approx 2k miles, all 4 rotors had to be replaced due to shaking during breaking. 3 months later, and another 2k miles, all four rotors came up warped again! After replacing all four rotors this time, the car continued to shudder during medium to hard braking. PCNA then ordered all four tires to be Road Force balanced and one of the rear tires failed. Tire was replaced under the tire warranty and now the car drives sweet!

Hopefully you have heard the last of this and I thank you again for your advice, comments, and concerns. I'm under no illusion the issue is resolved. I doubt a faulty rear tire has caused 8 rotors to fail but then again I am no engineer. I think someone earlier said it best, these cars are not "china dolls". Something doesn't seem right but I guess time will tell.

 

Glad that you got it back
Keep every single shred of paperwork and give us a 2k miles update.

 

Wow was this all out of pocket?

 

All cost covered by Porsche warranty except tire which was covered specifically under Pirelli tire warranty.

 

What is the Porsche explanation?

 

Zero. Zip. Nada. No clue. But it has cost them 8 rotors installed so far...

 

Let us know how many miles it takes to 'warp' the rotors again. I say this because a badly out of 'round' wheel/tyre combo will shake constantly, not just under braking. Further more, it would have to have experienced huge run-out issues if the car was shaking at the front when the bad tyre was installed on the rear. Somehow this sounds much more involved than an out of balance rear tyre.
Good luck.
Bish

 

++++1

 

I'd tend to agree with you and dux if it weren't for the fact that the most common reason for warped rotors and or glazed pads is the driver who overheats them with his driving technique.

Some people just have a propensity to gently ride their brakes in a way that overheats them during normal driving.. My wife for example just eats brakes and rotors and all I have to do is get in the car to see why..

We live in a hilly area and she rides them for long distances down hills instead of pumping them gently and then she jams the brakes on when stopping at a light. I can stand at a corner with a stoplight and just by watching how a driver approaches, slows and stops at a light if he will have eventually brake problems..

On some cars with inferior brake design it's much easier to overheat, but for Porsche it is obviously going to be harder. Unfortunately the brakes are so good, they tend to not fade much until you have really heated them up where as on some cars you start feeling the fade and let up..

But I do tend to be surprised that someone is having this happen with 2K miles, but I don't immediately jump to the conclusion that it must be a braking equipment problem and it is happening on all 4 wheels.. People never want to admit that they have crappy driving technique.. and that would be the most logical conclusion based on it happening more than once on 4 wheels..

On other threads with PCCB brake issues, it was suggested that PTV was possibly an issue.. (same issue of brakes warping and it isn't the driver).. but then ok, why all 4 rotors and not just the rear..?

I'm not suggesting there isn't possibly a bad part.. it may be something in the ABS system somehow that causing the brakes to ride. Anything is possible.. However the driver would seem to still be the most likely culprit so far.

 

What is the proper way to come to a stop at a light? Assuming you were doing let's say 60km/h before the light.

 

Let's put it this way. If you have the space on approach you slow down gradually and by the time you come up to whatever limit line your body shouldn't be thrown up against the windshield or restrained by the seat belts..

Not saying anyone should normally drive like an old lady.. just saying there is a smooth way to do it and a not so smooth way. And the not so smooth way generates more stresses..

Think of it this way as a physics problem.. If I have a 5000Kg vehicle moving at 50m/s that is a kinetic energy of 1/2 * 5000 * 50 * 50 = 1/2 mv(sq).. = 6.25 M Joules. That's the amount of energy that needs to be dissipated through the brakes to bring the car to rest.

If you do it over 500m vs say 100m then you are absorbing that energy in a much shorter period of time with much less airflow to cool/transfer that energy from the brakes. Thus the rotor / pads are heated to much higher temperatures. Bigger brakes have more mass to them and they can absorb a lot more energy, but there are limits.

Now take that same scenario and ride the brakes down a hill on the way to stop at that light.. so even at 50m/s there is a slight braking due the brakes dragging so they are already absorbing energy.. Then stop hard in 100m (or whatever).. Now the temperature is even higher and more prone to glazing of the pads or warpage. .

Not saying a good brake system like a Porsche can't handle it.. Personally I think you can abuse the hell out of them and there isn't much of a problem. The bigger issue is overheating them by gently riding them..

But repeat that same sequence dozens of time daily and over a period of time you are getting a lot of temperature cycles and things happen that aren't good.

Never thought of it much this way, until I was involved with some jet aircraft brakes and looked at just how much abuse they took slowing a heavy object in a short period of time.. sometimes they literally melt..

Also note that PCCB yellow brakes are notorious as I have learned at overheating, especially with track use. They are so good that they don't fade, right up to the time that they start breaking down and you never realize it is happening... So overheating brakes ain't as hard as one might think at times..

 

I can't believe your driving style is causing this. Not like you have been driving in the 24 Hours of Le Mans Obviously we all love our cars and try to do right by them. I am sure you have...

Of all the interesting recommendations, an electronics fault that is associated with the braking system has the most merit IMHO.

I hope the issue has been solved and keep in touch.

 

We have video of your wife braking.

 

Yes these can all lead to warped rotors....I have used some of these in the past for my "beater" cars.

 

Over the years we all develop engrained driving habits. It seems unlikely to me that the OP suddenly began to abuse his brakes to the extent that replacement rotors were needed every few thousand miles unless he had a history of this pattern.