Audiablo

The vibration/pulsing during braking I mentioned earlier had gotten worse. At one point, I knew it was likely the rotors as while braking gently on a ramp, I heard the left-front wheel go squeek-squeek-squeek instead of just squeeeeeeeeek.

The condition got worse, and I was about to make an appointment at a local dealer. But I had an idea that used to work on my 88 Cougar which was basically to really work the brakes hard, heat them up, and hope they un-warp.

Now the first interesting thing I noticed is that if you brake and accelerate at the same time, after a few seconds the throttle basically disengages. I guess the computer figures hey, the driver wants to stop and go at the same time??? Better choose the safest bet.

Well, I got the brakes hot anyway (this took only about 40 seconds) and lo and behold - no more vibration! I think the squeak is gone, too.

timcar

What's the matter? Don't Eskimos know how to turn a rotor?

Stu B

A technique I am truly not familiar with ;-)

Bollinger

weird, a little sudden acceleration prevention, eh?

Jim Will

A common cause of rotor warpage is to get the brakes nice and toasty, then stop the car. That causes the pads (which are always lightly skimming the surface of the rotor) to sit in one spot on the rotor. This causes excess heat to stay in that one portion that is touching the rotor, and the rotor cools unevenly. This can cause slighty warpage. Over time, slight warpage turns to severe warpage.
The idea of heating the rotors up and then letting them cool off slowly can often times work. I have used it many times on my last car (95 Nissan Maxima with tons of go-fast goodies).
I did notice this with the A6 this weekend. When driving through steady, hard rains, the brakes get thoroughly saturated. The first application will require more pedal pressure until those big brakes heat up an burn dry. Much longer than I expected. Not really a problem, but slowing down on an interstate exit ramp after cruising at speed for over 10 minutes can be a little interesting.

s4wood

Heating up a warped rotor can and will make the warping worse. Take it from the "King of Warped Rotors". If it is better...they weren't warped in the first place. Maybe you just has some rust built up on the rotor from the last time you washed the car.