I do have 1987 300d. Lately I have changed valves, valves guides, and valves seals. Once you start the car without exhaust and intake manifolds you can see the valves are still leaking oil. Just rise the engine rev. and sprays oil to the intake and blows oil from the exhaust valves. You can physically see it. I have changed the seals and valves because the car was smoking at first morning start. Before I have pulled the head of the car I`ve checked the seals the same way like I have described above.(took the intakes out and run the engine) The head is #14 but is not cracked. New valves, guides, seals. I`m going crazy. Any advice