I noticed some puddling of oil on the pasenger side engine shock mount, directly below the boost pressure control valve, which doesn't seem to be leaking, is there someplace else I can search for the cause?

P/s shock mount and engine mount arm being oily is often a sign of turbo drain gasket leakage.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)

I'll check it out, just replaced the drain tube, grommet & o-rings last month, put in a new gasket, maybe I didn't seal it well enough.

That's what did it to me... Mine was fine at the turbo, the oring was bad. The issue is that without removing the turbo, IMO you cant get the flange at the turbo clean enough to get a good seal... SO then what happens is that it leaks at the turbo drain seal and goes down.

Next time I have to do that job on a car Im just pulling and rebuilding the turbo for PM.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)