Good afternoon all,

I have a 2000 Silverado Step Side with a 4.3L Vortec. In looking specifically at the oil pressure gauge, I'm noticing that on the highway with the engine fully warmed at operating temp, the oil pressure seems to only get up to about 38psi. When the truck is cold and I first start it up the pressure climbs to about 60psi, and then comes down as the truck warms up. At idle the PSI seems to about about 20, but I hovering under 40 at highway speeds.

Any ideas?

 

Might try some fresh oil, but if the motor has some miles on it that is normal.

 

The truck has 157K at the moment, and even with the fresh oil it's still the same. Anything that can be done to raise it back to operating range? Could this be signs of a weakening oil pump?

 

It's possible but I doubt it is the pump. It is just an engine with some miles on it that has its tolerances increasing just a bit when hot. Around 40 PSI when warm is nothing to get worried about. We used to have an old tow truck that when cold would see about 15 PSI and then would drop to 5 PSI when warm idling and 10 running down the road. We ran it hard like that for at least 7 years before Hurricane Andrew had its way with the old truck. I have had luck with Lucas oil treatment in the past with trucks with low oil pressure. I would substitute a quart of oil with a quart of Lucas during an oil change.

 

Normal.

 

Each engine can perform differently from the next very same engine. Some engines will also have different characteristics then the next very same engine. ie: opporating temperatures and oil pressure.
Yours is a little low.. but close enough to normal, that you shouldn't worry yourself with it.
If your still concerned about your engine getting the lubrication it needs. Do a %100 synthetic oil change with a OEM filter.

 

Hey guys, thanks for all the replys. I appreciate the help. I got the truck with about 135K on it, and it's my daily driver but I bought it in the winter so I really just started going through it.

I think I'm going to do the Seafoam treatment to the crankcase before this next oil change and see if maybe it helps a bit. Might spring for some Royal Purple this time around, or possible the mobil 1 oil.

I'll let you guys know how I make out.

Thanks,
-Ant