i think am having a whining noise from the rear diff around 40 to 50 miles specially with no load ,,, cant find alot of data about our tiptronics and the rear diff ,

- is it possible to source ring and pinion with all the bearing
- can i buy a used rear diff alone or it should be with the tip as a one unit
-any sites that provide parts for the tip

regards

 

Check the wheel bearings first - probably a more common issue than diff.

 

I had a similar noise from my tip which turned out to be a diff. carrier bearing which I sourced from a bearing shop after disassembly-just use the number on the bearing,way cheaper & easier going this route.Our tips are made by mercedes & the porsche catalog does not offer much in the way of parts,so merc would be your best bet for internal parts.I know adam669 had a similar noise,but I think he is still chasing that one.Do a search as he's got allot of good info in his post's

 

Fuel pump? Mine had a whine and this is what it was