Hello enlightened ones,

my car has sat for 8 months. Meanwhile, I rebuilt the head, mirror-polished the combustion chambers, etc...The head was milled to bring the CR to 11:1. The engine has 150k. miles.

Now that I have gotten the engine going, I can detect, by ear and ,more so, using a stethoscope, a clear knock in cylinder #1 at crankshaft level. The noise is there at idle and when warm. When I pull #1 plug cable, the knock almost goes away. I am guessing rod knock from a bad rod bearing. A much fainter knock can also be heard at cylinders #2 and #4. The gas tank is full of AKI 97 to rule out detonation.

Passing by the local Volvo shop, I asked one of the mechanics for a rough estimate to do the rod bearings job. He declined, saying they wouldn't work on such an old engine and that Volvo bearings hardly ever go bad. He suggested piston wrist pins were a more likely source for the knock.

I am now planning on doing the repair myself for sure. Working from the bottom of the engine, I expect to be changing all rod bearings.

- If indeed I have bad wrist pins, will I be able to detect them with the head still on and the pistons in the block?

- What is the probability of finding bad main bearings as well?

- What other possible sources for the knock?

At it's stock 9.3:1 CR, before the mods, I am not aware that the engine knocked.
Maybe the higher CR has brought out all the impending weaknesses.


Thanks for your continuing patience and brain power...