Replace Suburban 5.3L oil pump

How do I replace the oil pump on a 2000 Chevy Suburban 5.3L 4x2?

You buy a service manual and follow the instructions.

But first you make REALLY sure you need a new oil pump.

It’s got 194,000 miles on it and my mechanic recommended that I replace it with a high volume pump. When the engine is cold, the oil pressure will drop to zero at idle, and with an increase in rpm, it will come back up. Even with the engine hot, at idle at a stop light the pressure will occasionally go to zero.

Something is strange here. Usually when the oil pump needs replacement you will have decent pressure when the oil is cold at idle and close to zero when the oil is hot. The classic situation is after a couple of hours on the freeway the pressure at idle on the off ramp stop line will drop close to zero.

With your situation I would have the mechanic put a calibrated gauge on the oil gallery tap and see what the pressure actually is. If the oil pressure is still low cold, I would check the pressure relief valve to make sure it is not stuck open. However, I think the relief valve is in the oil pump so you are already there so you might as well replace the pump.

Let us know how this comes out. Keep us in the loop because we are interested.

Thanks for your time and help.