Yes, the 350SDL engines have problems with bent connecting rods which cause the pistons to wear the cylinders oval-shaped. A friend of mine had a 1991 350SDL and his mechanic ordered a new block from Germany. $7,500 later he had a fine MB automobile again. Of course, my friend owned his car for years and maintained it by-the-book. Recommend staying away from that car unless you're a skilled DIY'er and have access to a donor engine.

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Fred Hoelzle