Thread: LS4 Oil Pressure Dilemma

Oil pressure problem remains the same. Cold startup pressure at idle is 10-15 psi. Lifters sometimes clatter. After 10 minutes of idling, pressure goes to 25 psi, lifters are quiet. Anytime the engine is revved beyond 1500 rpm, pressure goes to 40+ psi.

Every engine with oil pressure problems got worse as engine warmed up. This is puzzling.

I changed the oil (Quaker 5W30 full synthetic and AC PF63 filter), added 6 ounces of SeaFoam to the oil after reading that some people get "magic" results. We'll see what happens.

A side benefit of unplugging the sensor wires is that the shudder when stopping has gone away completely. As some have told me, the problem is the DOD staying in 4 cyl. mode when stopping. Problem is, the Service Engine Soon light stays on and remote start won't work.

Originally Posted by bocoogto

Oil pressure problem remains the same. Cold startup pressure at idle is 10-15 psi. Lifters sometimes clatter. After 10 minutes of idling, pressure goes to 25 psi, lifters are quiet. Anytime the engine is revved beyond 1500 rpm, pressure goes to 40+ psi.

Every engine with oil pressure problems got worse as engine warmed up. This is puzzling.

I changed the oil (Quaker 5W30 full synthetic and AC PF63 filter), added 6 ounces of SeaFoam to the oil after reading that some people get "magic" results. We'll see what happens.

A side benefit of unplugging the sensor wires is that the shudder when stopping has gone away completely. As some have told me, the problem is the DOD staying in 4 cyl. mode when stopping. Problem is, the Service Engine Soon light stays on and remote start won't work.

Have you replaced the sensor? The filter can be cleaned with gas but they are cheap so I just replaced mine when I did my sensor. 5w-30 is fairly thin oil, and your mileage is up there. Might want to run something thicker. Motor Medic makes a good motor flush used at oil change for higher mileage engines, I have seen results in the past using it. If you havn't owned the car since new it may not have been cared for as it should have been, and DOD is a dirty system as well. Aside from dropping the pan for the o ring and revised gasket not much you can do without getting dirty. Good luck.