Thank you for sharing your disappointing chronology.

The consensus seems to be that the engine was built with understrength connnecting rods. The head problems should have been cured by the time the 603.97 came out (first version had serious cracking problems if overheated, second version still had a problem with the head gasket blowing out into an oil passage at the front of the engine and hence into the chain case -- no engine damage MOST of the time, but occasional hydrolock from oil filling #1).

There are three versions of the rods, the last being some 90 g heavier than the first ones, engines with this rod set appear to have normal MB longevity.

MB officially denies all of this, of course.

I've heard that about 40% of the engines failed before 100,000 miles, very bad by MB standards, and if this is true, it points to a very definite design defect. I personally believe they should have recalled all of them and replaced the rods at least, but this is not really a safety issue so there is no legal requirement to do so.

They did replace a large number of engines under extended warrenty for original owners, but second and later owners get left out in the cold.

Peter

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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!