1986 K10 Possible Bad Oil Pump

[chrisrc84]

I have changed the oil, new filter, no leaks at filter or at oil pan. Either the truck is burning oil or the oil pump is going bad. Oil pressure doesn't go up like it should and I have plenty of oil in truck. My best guess is the pump is going bad but would like a second opinion about it. Don't want to go through changing oil pump if it could be another problem. I have no other ideas and Haynes manual is not very helpful with diagnostics.

 

[Chuzz]

Try replacing the oil pressure switch first. Odds are much more likely that is is defective. You could also get a fitting and a gauge to check the pressure. You don't state how many miles or which engine you have. And if you're not hearing rods knocking or valves chattering, I don't think your oil pump is going bad. I'm pretty sure it's just your oil pressure switch. If you have a light, they run less than ten bucks for a new one, if you have a gauge, probably thirty to thirty five. Good luck with it. I'm guessing you're running a 350 in it, right?

 

[SWHouston]

If you replace the Sender as recommended, I don't see why you shouldn't install a "T" at that time. That will afford you immediate access for an Analog Gauge for a quick check, or permanent installation at some point.

Beyond the questions ask about your engine...
What does the existing sender read at a Cold Idle, and at 2000 RPM ?
Then what are the pressures after it gets warmed up ?