As posted earlier, I experienced a catastrophic and sudden loss of oil pressure in my 1990 300E, 103 engine.

Today, whilst performing an autopsy on my oil pump, I found this inside (see pics below).

As you can see, it locked/ruined the pump instantly. The gear and bolt on the front of the pump ripped right off. There was a small tear in the pump screen that allowed the little part to pass into the pump.

By some incredible miracle, the engine is not harmed. I inspected several main and rod bearings and they are fine. They show 250,000 miles of wear, but no trauma.

My guess (and it's only a guess) is that this little culprit is from a valve lifter. It's flat on one side. There's a tiny hole in the middle. The other side is cup-like and polished, like where a pushrod might sit. However, I've never seen a MB valve lifter, so what do I know?

It may have been floating around in the engine for years after being dropped into the engine after a lifter failure/replacement? Or maybe it arrived in the sump recently, although I've heard no lifter noise.

What do you think it is?

BTW, about 250,000 miles and not a bit of sludge in that engine!

Thanks

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