My friend just got an S5 n/a engine with 140k miles. We did the poor mans compression test and both rotors sound strong. When we took off the exhaust manifold, the first thing we noticed was oil coming from the rear housing. Its not like a big puddle of oil but just enough to bother you. The rear rotor looks wet and the front rotor looks normal. What could have caused this AND most importantly does the engine need a rebuild?

 

either the oil control ring on the rear rotor are bad, or they put oil or atf in the rear rotor to gain compression

 

Thanks Black...

Any one else?

 

This will test the oil control rings.
While in neutral and warmed up, hold it to 5k for 2-3 seconds, then let off and rev it twice.
You should see almost no smoke.