8.1 L Oil Pressure?

[GLWilliams58]

What should I expect to be the normal operating oil pressure? And when does it get too high or too low? And what would cause it to get too high or too low?

Here is what I saw just this evening prior to and after changing to synthetic NAPA 10w30 with the 1060 NAPA filter and 7 qts of oil: I noticed 44psi idling prior to the change and 39psi idling after the change. Following that I drove to a store and found 44psi while driving at 50mph. When I got to the store it idled at 17psi. Driving home again 44psi, then idling in my driveway 17psi.

The 17psi on a hot engine seemed very low to me, but I am just learning about this engine and would like your input.

Thanks.

[GLWilliams58]

What should I expect to be the normal operating oil pressure? And when does it get too high or too low? And what would cause it to get too high or too low?

Here is what I saw just this evening prior to and after changing to synthetic NAPA 10w30 with the 1060 NAPA filter and 7 qts of oil: I noticed 44psi idling prior to the change and 39psi idling after the change. Following that I drove to a store and found 44psi while driving at 50mph. When I got to the store it idled at 17psi. Driving home again 44psi, then idling in my driveway 17psi.

The 17psi on a hot engine seemed very low to me, but I am just learning about this engine and would like your input.

Thanks.

[Marshall316]

Your pressures are perfectly normal.

[MikeT]

I'd suspect the intial 44 PSI at idle was cold oil. My pressure runs about the same 17 idle low 40's at speed.

[FrontRangeRVer]

Mine runs about 41-42 at speed....

[GLWilliams58]

Thanks for the replies. Great info.

[depchief]

The pressures you are seeing are normal for the 8.1. If you compare to other GM V8's they run higher at idle and operating RPM.

I have been getting very good miles per quart with the synthetic.

[JB Driver]

Recently I had this same issue. Contacted the Regional Service Manager for the Pacific Northwest for Workhorse Custom Chassis and was told the following: 1) Normal operating oil pressure on a hot engine is 30 to 40 PSI. Use AC/Delco filter specifically for the 8.1 engine only as they have had issues with restrict oil flow with other brands, especially the Fram filters. My normal operating oil pressure has been 38 to 42 PSI on a hot engine.

I recent had a oil filter fail, with an AC/Delco filter, and was having an apparent restrict flow with a oil pressure running 28 to 30 PSI. The fix was to change the oil filter and oil. Pressure came back to the normal operating range.