My oil pressure used to be a staedy 45lbs. Now when It warms up and I let it idle its been going down to around 30lbs. I cahnge the oil every 2-3000 miles. Is this an indication that the oil pump is going south? Its at the dealership now for compression test, leakdown test, borescope of clynideer walls for engine knock.

 

This 30 psi is safe level but could be indication of engine wear, probably not your oil pump though, when they fail the bypass circuit sticks open and you lose all pressure.Fwiw my Ls1 doesnt knock at all, just under 40 psi hot at idle with 5w-30.

 

Mine has stock thermostat and is runnin just at 40psi when hot after sitting at a stand still in traffic. Thinking of relocating the oil filter away from the exhaust system as sitting in Houston traffic tends to let the heat warm the oil up a bit. After running down the road again for a few minutes, the oil then cools down and the psi will gradually go back up at idle.

 

Supposedly, you should have 10lbs of oil pressure per 1000 RPMs. As long as your oil pressure goes up with RPMs, I wouldn't worry too much. Keep an eye on it, though and if it starts going lower and lower over time, you may need to go through the motor and have it reworked. (new bearings, etc.) If you ever have the oil pan off, replace the oil pump with a new one. Cheap insurance.