Twice now, the gasket on my 1983 240D oil filter housing has failed, causing my beloved car to spew oil all over the firewall and dumping quarts in mere seconds! Does anyone have any ideas what could be causing this? STP oil filter and Mobil Delvac 15w-40. Once it happened when warming up, and once about 1/10th of a mile down the road.

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-Jonathan

1983 240D "Bertha"

Which gasket is failing? There are four, the gasket between the housing and the block, the large O-ring and the two small o-rings on the pipe. Are the nuts coming loose when it fails?

It shouldn't cause a leak but the two o-rings on the pipe should be replaced and the hollow internal passage inside the pipe must be open, look for two very small holes on the sides of the pipe.

I'd use a Mahle, Hengst, Knecht, Mahle, MBZ or Wix filter.

I'd and have used the oil you chose but preferred Chevron Delo and Shell Rotella T. Just be sure whatever oil you use meets the MBZ spec.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

It’s the large O-ring. The nuts are not coming loose. An STP filter wasn’t my preference, it was just the only one I could get locally. I plan on upgrading soon though. As well, I do need to replace the two small o-rings and I will check to make sure the pipe is not clogged.

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-Jonathan

1983 240D "Bertha"

I'm wondering if there may be an issue with the O-ring supplied with that filter i.e., dimensions or material. Please keep us posted.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

This is the second O-ring it’s done it with, but both the same brand (STP). However the first one lasted over a month before it happened. The second barely a week. I’m going to order a proper oil filter/O-ring set today and we will go from there.

Did the oil pressure gauge drop down from "3" bar at idle on a HOT engine? Keep an eye for this as it could be a pressure relief valve not opening. IIRC, there is one on the oil pump and one in the oil filter housing. The gauge usually pegs at 3 cold and drops off to 2-1 at full hot idle. Upon acceleration even when hot it should immediately re-peg at 3.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

It always has, yes. Although since the first time it did this, the oil pressure gauge does not drop below 1 even when the car is shut off, which is new. But it’s always dropped down at idle and pegged again under acceleration. Both times this has happened, it’s been on a cold or just barely warmed engine.

https://www.peachparts.com/shopforum/diesel-discussion/378364-616-916-oil-pressure-too-high.html

For your reading pleasure. FYI, the lower oil pan is easy to R&R. The pressure relief valve could probably be cleaned in lacquer thinner or replaced but I think there are a few different ones. Oil pump failure is very rare, I'd be hesitant to do a pump replacement unnecessarily vs. an inspection/cleaning.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer