03 Yukon Denali oil pressure gauge problems

[humbo]

Just bought this Denali 2 weeks ago. 82000 miles, 2 owners. Noticed oil pressure reading 80 but didn't pay too much attention. Truck spotless.
Then I started to pay attention. Even after running at interstate speeds for an hour, oil pressure stayed at 80. Checked the oil this am. Engine dead cold after sitting overnight in 29 degree temps. Oil over filled by at least 1 1/2 quarts. Maybe close to 2. Drained that much out and it showed 1/4 qt low. Started engine let it warm up and idle for about 15 minutes. Oil pressure gage still on 80. Doesn't seem right. Would appreciate advice/comments. Yeah, I should have checked the oil before I drove it away from the sellers house. My bad.

 

[tsuintx]

Hmmm... IIRC, and I'm sure somebody will correct me if/when I'm wrong, the oil pressure and volt gauges are pretty much dummy gauges on these and only show something other than normal if there is a critical issue.

Hence, even if it was overfilled, the ECM didn't register a problem and kept it at 80psi.

The stepper motors in the cluster are known to fail, so if your gauge is not doing anything, that could also be the case. And, last but not least, the oil pressure sensor is also know to fail in these things, but if that happens, the gauge usually just stays at zero.

 

[OR VietVet]

Replace the oil pressure "sender" and when it is out attach a pressure gauge and get an actual oil pressure reading with cold and hot and revved engine. Have to remove the plastic engine cover and is at the back of the drivers side engine at back of intake. PITA.

 

[undy]

LS sending units are very problematic and have a failure history of doing exactly what you've described. Mine died in the same fashion on my Z06 and it's sort of a PITA to get to. I installed a "pig tail" to make future replacements easy.

No, they're real, not "dummy" gauges. Don't know where you came up with that???

 

[tsuintx]

No, they're real, not "dummy" gauges. Don't know where you came up with that???

The interwebs, of course.

But yeah, I think I mixed it with the discussion about F-body gauges which some people seem to have confirmed to be dummy.

 

[OR VietVet]

I gotta ask, what is a dummy gauge?