Rob... when I had the head replaced on my S38 motor it took the tech 15+ hours, covered under BMW factory warranty.
Also, replacing the head gasket on an S38 motor is an order of magnitude more difficult and expensive than the M30 in the M535i and can lead to some serious repair bills and If it isn't done correctly, disaster!

I would never pull the head to make sure the head isn't warped. Either there is a definitive reason to suspect a warped head, like an engine overheat and high leak down % or you leave the head alone.
Rod...

Rob wrote:-----------------
I think 15-20 hours is a little high. Second I think that I would replace it now and make sure the head is not warped.

Rob
M535i SIG Chief Technical Advisor
www.m535i.org

Hello all-

I have had a slow oil leak, which has been traced using dye/UV to the front passenger-side corner of the head gasket. My mechanic
whom I trust is advising doing nothing until it gets worse, then replace gasket, which he says could run $1500 (15-20 hours labor). I
have no other symptoms such as white or blue exhaust, discolored oil, oil in coolant or disappearing coolant. It barely leaks when
parked over night, just get a few drops worth on floor. In fact, they couldn't find it after running the car for 90 minutes, so I had to drive
it a few days. What prompted me to bring it in was I used a quart of oil in 2k miles. Yes I drive it fairly hard, lots of short trips (no
track). Car has 80k miles on it. I would appreciate any advice on: 1. should I just sit tight and monitor it? 2. should I do any other tests
now (compression)? 3. Is this common in the S38 at this mileage? 4. might the head be warped or cracked? 5. Assuming it is the
gasket and I have it done at some point, does 15-20 hours sound right, and what else should be done while it's pulled. THANKS a
million for any advice.