Porsche brakes

Hi,
I purchased front brakes and rotors from O’Reilly Auto Parts, for my 2006 Porsche Cayenne. The brakes were grinding while stopping the car, so I went to O’Reilly and talked to them about the problem. They suggested that I get different pads. I ordered different brake pads, installed them and returned the others. Now the second round of pads are making that grinding sound again while stopping the car. I checked the rotors and they seem to be fine.
Is there special pads that will not make that grinding sound? If so, where is a good place to get them from?

The dealer. Pricey, but better than O’Reillys, Autozone, or Pep Boys. They will be OEM, like the pads the car came with when it was new.

Do the pads and rotors meet the vehicle manufacturers specifications?

Or are these the cheapest pads/rotors provided by O’Reilly for the vehicle?

Tester

The first set was the cheapest, the second set was mid price, $116. Sounds like I have to go get brakes from a different place.

As was said above I would buy them directly from Porsche.

No.

You have to start all over.

Get brake pads and rotors that meets or exceeds the manufacturers specifications. This can be from any auto parts store. You’ll pay more for them, but there’s a reason for that.

Then follow any instructions that comes with the brakes for any break-in procedure and you won’t have any brake noise.

Tester

rmeuropean.com

They’ll have the things wear and tear and basic maintenance items you need for european cars

Did you thoroughly clean the new rotors before installing them on the car? They come with a surface coating to prevent rusting, but if that isn’t completely removed this can be a result. The better shops will get a big tub of hot water and soap and scrubbing pads and clean that surface treatment completely off both sides of the rotor before installing the new rotors.

If you didn’t clean the rotors thoroughly, that surface treatment is now on the new pads too. If so, replace the pads again and clean the rotors.

Maybe the grinding is not the pads. Maybe there’s a rotor shield rubbing or an exhaust system heat shield vibrating due to the change in engine stance while braking.
A heat shield noise is often mistaken for grinding.

Is this a base Cayenne or S, Turbo, or Turbo S? You might get away with the top level pads from O’Reilly’s for the base SUV, but the V8 possibly and both turbos surely need better equipment than O’Reilley’s advertises.

rear pads and rotors are ok? you did inspect the inside surface of rear rotors? not just the outside?

You got cheap pads and rotors and your are paying the price for it. Why go cheap on a very expensive (and very heavy) SUV? If you don’t go to the dealer for these parts, at least buy really good stuff. Brembo (or similar high-end rotors) rotors and the most expensive pads they have.

I imagine that @George is correct re the new rotors not being cleaned. The hard, waxxy coating that is applied to rotors and clutch pressure plates to prevent rust causes DIYers a lot of problems when they don’t follow the instructions in the box.

@Mustangman - I’m betting this was bought used, a seeming ‘bargain’ because of the huge depreciation these go through.

@texases: Yeah, I was wondering why someone would buy a Cayenne and then put the cheapest pads they could find on it.

The problem with high-end anything seems to be that they are very prissy and temperamental about maintenance. This seems to apply to cars, computers, homes, boats, and people too.