Okay Brick Sages, I have bought a clean little 1988 240. Previous owner states that the oil filter failed and it spun a rod bearing. I bought it under this assumption.

Now, he also says that there is good compression, 140-150 lbs per cylinder. He also says that there is oil in the antifreeze.

I towed home and then stated the car, the knocking was more to the top end almost like a piston hitting the valve. No skipping -- just the high pitched knock.

Pulled the head off, nothing obvious at all, there was some hard plastic substance in the top of the head ...almost like a hard vacuum line. Turn the head and no noise at all. We then spun the bottom end (via starter) and again nothing at all.

Question is, what care the possibilities?? Could a cracked flex plate knock?

Inside of the engine is very clean...almost too clean!

Any ideas at this point is welcomed!!

randyB