I own a 1990 190e 2.6 with 103,000 miles on it. It was just recently put in a german specialty shop to fix a oil leak. They told me they replaced the head gasket and did a valve job, however about a week after i got it back the leak is back. I am loosing about a quart a week. It doesnt smoke so i know i am not buring any oil. any pointers would be greatly appreciated.