Oil pressure low

Old oil never makes as much psi as new oil. Older it gets, less psi it makes.

rockola1971 said:

Those value look perfectly normal for the mileage you have. What does the pressure goto when cruising at 55pmh? How about idle to 35 mph? Do you have a standard 3.73 rearend?

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Idk it’s like, maybe around 30 ish as of right now it’s acceptable since like I said I just did an oil change. Drove 300 miles around Galveston and Houston. HOT idle after 2 hours of driving with this fresh OC in idling just a hair above 20 PSI. Normally running idle to 35 it’ll shoot slightly above 40 psi. And it’ll run at 30 or so idling at 55 psi. Rear end not sure. It’s a z71 has the locking rear differential via traction control button. It’s a 2WD

houstontaylor said:

Mine was recently intermittently going down to 20 psi before I replaced the oil pressure sensor. Maybe the heat when the engine is warmed up is affecting the sensor but I don't know about the new oil/old oil aspect.

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Is your pressure fine now? Post sensor replacement.

Another reason I bring this up is by comparison.
We have a second 2006 Chevy Tahoe 5.3 L, LT trim. it’s got 300k miles on it. 160k miles of straight neglect and abuse, as it is a work truck. Now my brothers vehicle. It makes fantastic oil pressure. Around 60 on the highway no problem. Idles at 40 all day long even on old oil.

This is mainly why im concerned about mine. As mine to my knowledge did not get anywhere near that level of abuse.

And by abuse I mean complete mechanical negligence until something broke basically. Very rarely did oil changes on it. (This was not my vehicle, I take care of my vehicles lol.)

If you overfill the oil after the motor is warmed up at idle and the pressure goes up by 5/10lb you can verify if the O ring on the oil pump is bleeding air into the system or … replace the O ring, it’s bad.

Be sure to drain extra oil out b4 u drive it. You could also swap out the oil pump and replace with a HD version.

petethepug said:

If you overfill the oil after the motor is warmed up at idle and the pressure goes up by 5/10lb you can verify if the O ring on the oil pump is bleeding air into the system or … replace the O ring, it’s bad.

Be sure to drain extra oil out b4 u drive it. You could also swap out the oil pump and replace with a HD version.

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Wow, can't believe I never thought of that. How much extra oil does it take? Could you just park nose down on a hill or front wheels in a ditch, to get O-ring under oil?

1-2qt

It is also possible that the pressure spring in the pump is getting weak.