Jeff:

There is a relief valve, but I dont' know where it is off hand. A scored seat will do exactly what you see.

I'm also not sure where the oil pressure sending unit is, but that is where you need to attach a working mechanical gauge to check the electric one.

I have an "aftermarket" CD manual and a Mac (so I cannot use the table of contents or index easily), but there is an index burried on one of the CDs, it's eaisre to use that than to look at each and every pdf...

Note that you only need to look in the engine section, under lubrication, so once you determine which group that stuff is in, you only have to look at pdfs with that prefix number.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!