UPPER ENGINE NOISE on 2000 Cadillac Catera

have a 2000 3.0 catera, had a water pump put in, now I have an upper engine, lifter like noise, like no oil to the top end, oil pressure good, car was fine before they did oil pump, any ideas?

2 answers
The first part of your question said "water pump" was replaced but last sentence says "oil pump". I presume you had meant the water pump was replaced and the noises you hear now were not present prior to the water pump replacement. Your engine has a timing belt ensure the noise is not related to anything worn inside the cover (tensioners, idlers ect..), to diagnose the source of the noise I would remove the fan belt that drives the water pump and se if the noise goes away if it does there is something wrong with the water pump or belt alignment. Your car has hydraulic lifters (non adjustable valve clearance), if the passages "clog up" the lifters can make noise. Try using a product called Risolene in the oil, it is high detergent, low viscosity additive that cleans out the passages and may address the problem after a few oil changes, but get it checked out as it may be a sign of something serious and should not be neglected.
what was the problem? did you fix?