Hi All,
My 997 has a weird habit that is starting to bug me. When the car starts up in the morning. On the first brake, where I can hear a very distinct “clunk” coming from the front, not sure if the sound is from the brake or the axle. It does not matter the speed or the brake force or forward vs. reverse, and only on the first brake. After that the car runs and stops fine, no noise when turn or going over bumps.

Took it to the dealer and left it over night, return early the next day and start up the car with the tech next to me. Put it into “D” and let the car start rolling forward, lightly apply the brake and then a loud “clunk”. The tech hears it and said it was normal. The tech also check the front under the lift and said everything is tight. But my heart skips a beat every time I hear it. I also notice if the car sits for a longer period, the clunk is louder.

Any other car out there do the same thing?

 

I would check for any play in the front trust arms.

 

Might be pad shift? But mine does not do it, but been in plenty cars that do.

 

might be slight "play" of front brake pads inside their housing.
Mine does the same on the condition car's first movement is opposite to the last.
i.e. stopping at night while car was moving forward and starting in the morning going in reverse, or stopping while reversing and then starting going forward.
It happens ONLY in the very first movement.

Cant explain it any better...

 

I have the same issue every time I back out of the garage. Glad it's not just me.

 

I have a similiar issue when I back out and turn the wheel left. It sounds like it coming from the front passenger side.

It seems to only happen when it is cooler outside and the car has sat for a while.

 

Since dealership could not find anything wrong, then it sounds like it could simply be overnight rust on the steel rotors. First application may be noisy and "grabby" until rust is cleaned off - quite normal.

 

It does not sound like sanding rust off (btw turbo got PCCB), I know how rusty rotor sounds like after washing the car and sit over night. This sounded like something bang against something else. Like I said the tech did check everything and said nothing is loose.

Glad to hear I'm not the only one. Tech told me its the car saying "Good Morning!"

 

I hear it too. I attribute it to the tires flat spotting and sticking to the concrete and also rust on the rotors.