I have a 1990 240 DL wagon which has developed an oil leak.  It seems
to be dripping and smoking on the exhast manifold toward the
front-right of the engine.  I installed an IPD flame trap kit thinking
that it was just building up pressure and leaking out the cap.  Going
up a steep hill on the way to the Oregon coast it got very hot and
started POURING out smoke.  I pulled over for fear of fire but once it
finished smoking and cooled off I was back on the road.  I took it to
the dealership and they replaced the right side valve cover gasket,
"fixed" my oil cap, and gave my flame trap system the thumbs-up.  They
said the engine had so much oil on it that they couldn't be sure where
the leak was coming from.  This didn't fix the problem.  I don't fault
the dealership but would feel more comfortable diagnosing, if not
fixing, this myself.  I have read over other group postings on this
subject but would still appreciate some input.

Thanks for any input!