For a long while I have had oil leaking from an �82 Diesel Westy. I think though the problem could apply to the boxer engines also. Oil was leaking from the heads, main bearing seal, all the motor seals actually. The leak only happened when I would go on the freeway for a few miles.

It turns out that the pressure relief valve in the oil pump was stuck. My thanks to all of those who gave me suggestions and to Dan Snow who suggested the oil pump.

Scot