Knocking sound in 300D

[Walter K]

Gents,

I looked at a turbo 300D today (617 engine)that was reasonably maintained. It had a little less than 200K on the odometer, and from looking at the car, I believe that is a reasonable figure.

The engine started easy, had minor blowby, but had a pronounced knock, like someone hitting the engine with a hammer. I knew the car had a knock before I got there, and was expecting either a vacuum pump problem or an injector knocking. I don't think the pump was any part of the problem. The oil pressure at idle was 2 bars, and 3 when reved up.

I loosened the lines on the injectors, and the knocking diminished on cylinder #2, but did not go away. I swapped out the injector with a rebuilt and spray tested injector, with no change to the sound.

The car smokes btw.

The only thing I can imagine wrong after all this would be the con rod knocking on #2.

The PO had said that knocking had started 6 or nine months ago and just steadily got worse.

Anyone have any ideas? Did I miss anything obvious that I should have looked at?

Thanks,

W.