1996 a6
 

my sons 1996 A6 leaks oil BUT only after it is turned off. i have put cardboard under it and ran it for 30 min hoping to get some idea as to the leaks location. no drips till after it off and then it leaks heavy all around the lower oil pan i did replace lower gasket. before i go further i need to understand why it would only leak after it is shut off. i have read many threads and have done multiple searches but found nothing to explain this problem directly.
thanks for your help

Hi

Sorry to hear. It could be the rear main seal or the cam seals.

Here is what I would do. Go out and buy about 40 bucks of brake cleaner. Jack the front end of the car and from the top and bottom side. Completely clean off all leaking fluids.

Then get a dye tracer, drop it in the oil. Drive for an hour. rejack up and use a UV light to see where it is coming from.