Here too looking for any repair info on this issue.
I just bought an 08 Cayenne from an indy dealer -As is No Warranty - They wouldn't offer one.
Engine ran fine on test drive of about 10 miles - no problems evident anywhere - vehicle looks factory fresh from top to bottom.
Drove about 65 miles home with only one large puff of blue smoke on launch from light- ran fine save a slight miss at times.
Next day changed oil Mobil 1 0w40 with Mahle filter and vehicle close inspection - looks better than suspected everywhere.
Following day drove around town 20 miles or so low R