2001 Silverado V6 4.3, just replaced the intake gasket as there was coolant getting into a combustion chamber... also new engine coil, cap and rotor... truck runs nice, but now an oil pressure problem? Cold start I'm at 40, after warming up drops to 20, and then goes even lower. What am I missing?

 

Not sure about the 4.3L but Mechanics are removing the screen on the oil pump scavanger pickup tube as it gets clogged up. Also I have heard on some of the newer models that the pickup tube in the oil pump has orings that wear out so it doesn't get good suction. These are just some thought for you. I have no idea what your oil pump assembly even looks like, you'd have to get a repair manual and look it over.

 

Egads - I've just had 2 separate mechanics tell me that there is a small clacking sound coming from the engine, and that diagnostics are showing misfires... most likely I have a nick or gap in a rod / piston that is letting the oil get through faster and not hold the pressure. sh**!~