Hi I recently purchased a 2003 996 C4S Tiptronic, Its my first Porsche and also my first Auto gearbox. I notice when cold on start up there is quite a loud whine when breaking and changing down its not as loud or an issue when warmed up. Is this normal or is there a possible gearbox, Diff or brake issue that needs attention.

 

Can you tell if the noise is coming from the front or the rear? If it coming from the front then it's most likely your front differential. From the rear, it's most likely the gearbox. How many miles has the car been driven?

 

personally I would have the tranny and differential fluids changed,might solve the noise

 

Does the whine or noise agree with vehicle speed? The noise could be from the secondary air injection pump which runs sometimes for a minute or more when the engine is cold. In some cars this fan can be rather loud. Often the onset of cold weather has some owners reporting some strange noise that is the secondary air injection pump.

But if the noise tends to track vehicle speed this is likely not due to the secondary air injection fan.

You'll have to enlist the help (ears) of an experienced Porsche tech to give a listen and advise you.

 

Thanks for the responses, the whine is defnitely coming from the rearand is most noticable when cold and only when breaking and its changing down I will get an expert to listen and change the gearbox oil to see does that help

 

Let us know what they end up figuring out it was and post a few pictures of your new C4s when you get a chance