2000 Yukon XL High Oil Pressure

[Joronimo]

Anyone have any experience with high oil pressure in a 5.3L V8? I am currently seeing about 60 psi at idle and 65-70 at part throttle. I just changed the pressure switch and did an oil change to Castrol GTX high mileage 5W-30 with a new Fram filter. Im guessing its a bad gauge, all the readings are using the factory gauge. I am in an apartment so I don't have the best workshop so I don't want to hook up an external gauge if possible but I can if that's the best way to figure this out. The truck has about 160,000 miles and doesn't get driven much right now, partly because of this issue.

Any advice would be helpful, thanks!

 

[rayra]

Those numbers aren't really a serious cause for concern. 40-60psi is common in these motors. Slightly elevated with fresh oil is normal. There are other reports of as high as 80psi at high RPMs

But if it really concerns you, you could use a scan tool to see what the computer is getting from the sensor. The gauge stepper motor might not be correct. If you have an android phone or tablet, you could use the free Torque app and a $15 bluetooth OBDII dongle / transmitter and see the actual pressure data. That might be easier than hard-mounting an oil pressure gauge, if you don't already have the hardware.

On the opposite end, GM doesn't even consider the oil pressure to be too LOW on these motors until its in single digits.

 

[Joronimo]

Ok, thanks. That's pretty much what I have found through internet research. The gauge started to move around about 6 years ago so I'm guessing its just a bad gauge. Ill get the OBDII scanner and see if there is anything and go from there.

Thanks!

 

[fiddypal]

I have a v6 silverado 1500 (2014) and it does the same ****. Mash the pedal hard and fast and oil pressure goes up near 80, idle usually around 40ish. Normal from what I have found as well.

 

[rayra]

Really seems to be the case with these LS/LM motors. must be the orientation of the pump design. I don't recall the older small block chevys having that much range in the pressures.

If you start getting very low pressures on a high mileage engine of this type, consider replacing the o-ring on the pickup tube, and maybe a pump replacement.
http://www.expeditionportal.com/for...ckup-Suburban-Yukon-etc?p=2116569#post2116569

And at that point of engine surgery might as well change the timing chain set while you are in there.