OK so I have a strange issue going on with my truck. 2011 4wd with the standard 5.3L engine. I have owned this since new and have always stayed on top of oil changes and maintenance. The truck now has 130K miles There seems to be plenty of oil pressure, no valve or lifter clatter, I replaced the valve cover and stopped losing oil, and finally had a mechanical gauge verify pressure
Here's what happens Oil pressure stays fine for weeks, then suddenly as I'm driving the gauge drops slowly toward 0 and eventually the warning light comes on than the "ding of doom" goes off. Sometimes I get a P0521 , sometimes not. Sometimes restarting the engine resets the pressure on the gauge for a while, recently I have discovered that if I change the oil filter (I usually use Delco) the issue goes away. So here's what I have done so far as this has been an intermittent problem for years, but now it's happening at more frequent intervals.
So 3 years ago dealer replaces the oil pressure sender and screen, a few weeks later - happens again and they replace the oil pump and sender again, while they are at it they add the baffle to the oil pan. 2 years ago get a consistent P0521 so I replace the sender and screen again - problem goes away. 6 months gap problem returns intermittent p0521 so once again check wiring, replace sender and screen . It's at this point I realize that an oil change "resets" the issue, my guess it's really the filter change. I switched filter brands and it didn't seem to make a difference. I am so frustrated with this and wanted to see if anyone had any ideas.
So.... if it's electrical what would replacing the filter matter, if it's a stuck bypass then why do I get the P0521?
Here's what happens Oil pressure stays fine for weeks, then suddenly as I'm driving the gauge drops slowly toward 0 and eventually the warning light comes on than the "ding of doom" goes off. Sometimes I get a P0521 , sometimes not. Sometimes restarting the engine resets the pressure on the gauge for a while, recently I have discovered that if I change the oil filter (I usually use Delco) the issue goes away. So here's what I have done so far as this has been an intermittent problem for years, but now it's happening at more frequent intervals.
So 3 years ago dealer replaces the oil pressure sender and screen, a few weeks later - happens again and they replace the oil pump and sender again, while they are at it they add the baffle to the oil pan. 2 years ago get a consistent P0521 so I replace the sender and screen again - problem goes away. 6 months gap problem returns intermittent p0521 so once again check wiring, replace sender and screen . It's at this point I realize that an oil change "resets" the issue, my guess it's really the filter change. I switched filter brands and it didn't seem to make a difference. I am so frustrated with this and wanted to see if anyone had any ideas.
So.... if it's electrical what would replacing the filter matter, if it's a stuck bypass then why do I get the P0521?