Friday morning me and a family member pulled my engine/tranny out of my 89 IROC. Today we sat down and tore it apart, looking for what was causing the knocking. The cam bearings were pitted and had some real shiny spots, some were alot wose than most, one even had a groove in it. So im thinking I caused the problem when I replaced my intake gasket, there was a bunch of black oily tree bark looking crap in the cam valley and I cleaned it out, but Im thinking if some got down in the bottom end, it could have caused all the pitting and scratching in the bearings? Just some peace of mind for me, the block and heads are at the machine shop now, so ill have a new engine soon pretty much. Thanks!

 

sounds more like a crank bearing. find ones with copper showing there the ones that are making noise

 

The crank bearings were screwed also, my main question was if when I cleaned out this oily crud out, if some got into the bottom, could it pit and scratch the bearings like that(cam and main), and if it would make the engine knock. Thanks!

 

The gook itself wouldn't damage the bearings; but it could plug up the oil pickup screen and cause oil starvation.