I am looking at a 1983 300TD wagon that has a significant (owner reports 1 qt. per month) oil leak. It appears to originate from just behind the A/C compressor. Not able to have engine cleaned and then test for leak. Vacuum Pump gasket, maybe? Many thanks.

Probably the front main seal. When it goes will throw oil all over. Not hard to replace, not very expensive. You would need to clean it up and check to see where the oil comes from, but threre aren't many places that much oil can get through in the front of these engines.

There is also the possibility a bolt from the air conditioning compressor support bracket has fallen out. One of these bolts fits in a tapped hole in the block that can penetrate into the oil supply or drain channels. I have had this bolt fall out before and it very quickly gets very messy. Hard to see without a good cleaning. Good luck, Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Jim, if the bolt you refer to has fallen out, then can spray/steam cleaning be dangerous? Will check that one forst. Also appears to be a big leak inder the oil filter housing - looks like a bad gasket? A real mess down there.