since you do not have a knocking noise and the oil level and condition are good...it is more likely to be a sensor reading issue an not a true low oil pressure condition.

I have seen bad aftermarket sensors...haven't seen many wiring problems but it should be properly tested to rule out.


imo I would replace the screen first. its cheap.

 

Thanks, but can't take the credit, wasn't my DIY!

Knowing what the issue was, and it now being one of my wife's infrequently driven dailies, just got around to this. Also needed an oil pan gasket (web-$19.32), also which I knew about, but didn't get around to either. In this case pressure was sitting a flat 0.

I've got a hook-up thru one of the Service Writers at a Dealership and pay cash to have a lot of things done with one of the respective line techs at the Dealership. Bought both parts ahead of time and had them both installed $200 cash. Wish I had read about the screen, I would have had that done also (cheap insurance). Do things when I can, have the talent, but little time, and currently at eight vehicles between my wife and myself. Just put a set of new shoes all the way around (not at the Dealer) and had the alignment done while it was on the service floor.

The bad news, since my original posting...
WTF, motor mounts were bad (I had suspected) and bought at pair that a Tech had in his stash and he installed for cheap. A "Service Suspension System" message popped up... WTF, $501.35 retail for the pump (found it for $215 OEM New), and $455.60 EACH!!! for the shocks (still searching), which we won't know leak until the pump is replaced. Good god! And now the cluster lights (the white lettering and the blue shift indicator and message center) are dimming up and down on their own, and the rheostat switch works and doesn't work but can't get them upon bright. They do that on their own, sporadically. One of my Tech buddies says he can tell where the failure is with the computer, as it could be the control module and not the switch. This all to be done when I get back from a Thanksgiving trip to my Daughter's in CO. Maybe get around to the impact sensor and the level sensor upgrades for the alarm system while I've got it in, so my buddy at the Dealership can tune them into the control module while he's got the computer running. lol

Back on the subject of oil pressure, all of a sudden, I have what was described in the first post (bouncing back and forth from 0-80), happening on my '03 2500 Burb 6.0L, except no CEL, just a warning signal every time it drops to 0. Gonna' do the sending unit and the filter screen this time, on this one. Have to look around some threads, maybe they placed it in a better location on the 6.0L

Hope I didn't hijack the thread too bad!

Everyone...
Have a Great Holiday Season!

Morav

 

great post! i hope its as DIY as you make it sound!

 

It is extremely important to use OEM switch for replacement. I learned this the hard way! I believe the root cause of the switch failure is the Active Fuel management and the pressure relief valve in the oil pan. If the relief valve doesn't function correctly, I think this causes the switch failure. The best money I have spent is $200 for the deactivation module from Range. Plug it in to your OBDII port and it turns the AFM off. The first thing I noticed was the elimination of excessive oil consumption (@186k miles). The next thing I noticed was, believe it or not, improved fuel mileage from 15.7 to 16.3 mpg. No AFM, no switch failure.

 

Also, to get the screen out, use a dental pick.

 

Tigerfan,
If you're looking to replace the oil pressure sensor because of a low pressure reading and a subsequent OBD code indicating a bad sensor, you might want to read this thread before you dive in (literally), as the issue might not be a bad sensor, but a blocked/dirty screen as farmit is suggesting. If you do end up replacing the sensor, definitely clean the screen/filter WYIT.

 

Hey guys, I have the same issue (Low Oil Pressure Switch Sending Unit Silverado 2003, alarm keeps going off, normally pegged out at 80 but fluctuates down to 0 at times) and know for a fact it is the switch. I had the engine pressure checked and it is fine. I travel a lot and am not sure when I have the time to replace the switch. Is there any way that one knows of to disengage the alarm for the Low Oil Pressure Alarm so it won't drive me crazy? I can't seem to find that alarm fuse if there is one.

 

 

I think I have this problem,,,,, all of a sudden,,, oil alarm sounded off,, message no / low oil pressure,,, gauge at zero,,,,,, YIKES !!!! But oil on dipstick, and no rattle or common noises from a motor with true "0" oil pressure,,,,,,,,,,,,,,. Oil gauge will move up a little then fall back, with each restart. So,,,, looks like a a sensor failure, yes ?

 

That would be a yes, Good luck with your project.