I own a 1978 911 sc with 47000 and the car sat for 16 years or so without being driven. The car was not stored properly before parking but was kept in doors all those years and is in great shape. I had a local/repitable repair shop do a number of things to get this vehicle road ready and I'm happy with all the things they performed as I now put on aprox: 800 miles of great driving. However is there something difficult about sealing the valve covers properly on this vehicle. The valves were adjusted and new seals were replaced. I returned a second time due to oil leaking to the ground after parking a day or two. The tech. found a bolt slightly loose and retightened but still have same problem at left rear. Appreciate any good advice. Thanks Mike.

 

The 911 covers are prone to warping. You can replace the paper gasket, but if the cover is warped, then it will just leak again. You are stuck with buying new replacement covers, or go with aftermarket billet aluminum covers with the updated 964 rubber gasket from Imagine Auto.