03 tahoe oil pressure issue help

[Babybrat88]

Ok where do I start so everything is good driving along and notice my oil pressure gauge flat lines to zero there was no change in motor and I'm in traffic so I keep driving and then it pops back up to normal. This happens about three more time in a time frame of six months. Then I notice that my oil pressure gauge is resting at about 20 and when I hit the brakes goes down closer to the zero make and the light is letting me know low oil pressure. I had also noticed a leak started. So I got a new oil pan gasket and pick up truck o-ring and replaced that. Start it turn it off leaking still so I got a new oil pressure sensor. Start it now there's a knocking noise. Shut it off still leaking. Could I need to replace the oil pump it self. The oil level and oil pressure lights are both still on. My oil level is right where it should be on the dip stick. But I haven't full determined where the leak is actually coming from on the pan but looks to be from on of the bolts. I don't know what else to do or check and advice would be helpful please and thank you.

 

[strutaeng]

Sounds it could possibly was low on oil (?)...and you ran it dry enough to damage a rod bearing.

Does the knocking even go away at this point? Does it increase with RPM? Drain the oil and see if you have any glitter. How did the oil pan look when you removed it to replace the gasket?

If you decide to replace the oil pump, I would open your old one and look for any scoring. If you have deep grooves on the gerotor or oil pump housing, chances are debris ran throughout the engine and you should rebuild or replace the engine.

I have a beater truck that leaks fluid like nobody's business. I hardly drive it. Once I was driving it and the oil pressure needle dropped to zero when I took off, then climbed back to normal...turns out it was low on oil. Doh. I'm glad I checked because I could have damaged the engine if I kept driving it like that.

 

[Fless]

Any particular reason that the replacement o-ring was for a pickup truck?

 

[Babybrat88]

I thought about the o-ring being the wrong one too. Cause it did look different than the old one.

I'll drain the oil and check it out.

 

[nonickatall]

In my opinion, the first step is a correct diagnosis.

In Germany, they say: Sometimes you have fleas and lice...

First, determine whether the oil pressure is really too low or whether the oil pressure gauge is incorrect.

To do this, remove the oil switch from the engine and connect a pressure gauge to check the actual pressure.

Using this information, you can determine whether the oil pressure or the pressure gauge is faulty.

Knocking noises can have other causes.

From there, you can then continue the diagnostic process to find out why the engine has too little oil pressure or why the pressure gauge is faulty.

Too little oil pressure of the engine can have various causes, from the O-ring you replaced, to the pressure release valve in the oil pan, to the oil pump, to a worn-out engine.

I also had poor oil pressure in mine at first, so I replaced the O-ring. That improved things a bit. After that, I added 1 liter of diesel to the engine a few kilometers before each oil change for three consecutive oil changes. This stopped the hydraulic lifter from ticking and almost eliminated my oil pressure problems.