Clogged oil pressure sensor screen of course. 4th time in maybe 5 years.

For anyone wondering, if you are not at home you CAN limp it home without killing the truck. Just requires restarts and constantly watching oil pressure gauge. Enjoy!

2011 Yukon Denali Hybrid Brake Repair how-to | Lost oil psi while test driving the 2011 GMC Yukon!
https://youtu.be/2SRTw1hAtyc

 

2009 so +13yrs old and at +266k miles and never had a clogged oil sensor screen. I do use full synthetic 5W30 and change at 5,000 miles or less. I suspect that people following the Oil Life Monitor are sludging their engines to death?
Not saying that is the issue but something is different? OP how many miles on your 2011 What oil do you use (synthetic/partial synthetic/conventional) and how many miles between changes?

 

Good to know - 145k miles. Only run full synthetic…when first got the truck at 65k did Mobil 1 5w-30 then switched to Rotella 5w-30 T6 for a while but when that got hard to find I used Pennzoil high mileage full synthetic 5w-30 last spring and consumed a lot of oil so I went with Mobil 1 and 10w-40 for summer and only a minor change in consumption. I went back to Mobil 1 high mileage 5w-30 after changing it this last time. All configurations clogged at some point.

I typically change oil at 20% so yeah I need to get in habit of changing every 5000 miles like I do with my other cars.

It seems to happen when the weather turns cold (Michigan). Not sure if that coincides with low percent life on oil and maybe bypassing a clogged oil filter but it is interesting how that carbon can get to the screen.

 

the afm on all these trucks are just weird about which ones fail and which don't. I see posts of people that don't do anything special and they never have an issue, and those that fail all the time like clock work. gotta be some reasoning to it, but its hard when they go thru 2 or 3 and sometimes many more owners in the 200k or so miles these trucks seem to average. I always see them at the top of the list as highest average mileage vehicles and find to had to believe everyone is having engines replaced when the afm fails every 150k miles.

I do believe it's oil quality related issue, but what can ya do you know. if you have to change the oil every 3-5k miles with high priced synthetic to keep the afm from failing in return you get maybe 1mpg? I don't know the math there, but at some point bypassing the afm and just running 10k on cheap oil like the older trucks do without issues would be the cheaper route.

don't mind me, just venting on this afm and clogged filter crap I've spent way to much of my time researching haha.

oh yeah, oil filter, gm changed their recommended internal bypass psi on their newer direct injected LT with the afm stuff from like 12psi to 22, might not be exact numbers from my old memory lol but that and a much longer filter hopefully lowering in in and out pressure differential seems to me like it would filter much more of the oil, right now the filters are bypassing most of the oil at any rpm much over idle. so I cross referenced and use wix. there's 2 to pick from 57045 has the original 12-15psi bypass, but is much longer, 4.8in over the 3.4in 57060 called for, puts its just a touch above the bottom of the oil pan and WIX 57502 is 4.1in, little longer than stock but with the higher 22psi bypass.

​​​​​​with all that said, I have afm bypassed, which removes the little filter under the oil pressure sensor since oil doesn't flow thru there anymore, it just dead heads against the sensor, no need to fliter it. run the 4.8in filter and change my oil with mobile 1ep sooner than the oil life meter says. blah. haha
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Not a bad call, I have considered putting in a longer filter for the sake of having more filter media but have stuck with the ol PF48 from ACDelco.

Oddly enough my 82xxx mile 2019 6.2L Denali uses 0w-20 and pressure swings freely from about 23psi warm idle all the way up to 65-70psi when standing on the gas. No oil consumption and fairly clean still later in the oil’s lifespan.

 

newer diesels seem to run very clean, I've got both at work, these new Cummings after 500hours the oil comes out clean, the old ones after the first start on new oil it's jet black. kinda crazy.

the 0w20 is crazy, I've almost been tempted to try it just to see what the oil pressure would be like, thinking of the this variable displacement pump. could keep the pressure up, might be a little mpg in it but such a waste out of just curiosity.

the funny thing about all this, I've run 15w50 conventional bulk oil in my old 96 tahoe for over 150k of the 325k on it with whatever on sale filter and it shows no signs of engine wear or build up in it, I don't even keep track of the miles just change it when I think about it. it was my daily driver for year and years.

new tech new problems


oh the higher mypass pressure oem part number is pf64 just for info.

 

Heres a follow up for anyone who has oil pressure drop in the future!

Fixed Low Oil Pressure Issue on GMC Truck | Oil PSI Sensor Screen Replacement | P0011 P0521 DTC

 

mine is at 45-70PSI depending on the RPM of the engine warm idle is 45psi... I use a chip to turn of AFM (range)

 

Also your'e never going to fix it because the actual problem is the oring on the snorkel oil pickup tube... this can be confirmed by overfilling the engine (loook it up before doing this test)

This is a very common issue

instead of wasting oil just replace the oring

 

that's not exactly true, while the o'ring is a common failure on the ls engines, if you have a engine with some build up, you pull the screen and see it's dirty, replace it and your oil pressure returns. it was the screen. this screen filters the oil going to your afm solenoids and down to activate and deactivate the lifters. as the lifters wear more it can be a good amount of oil flowing thru there. if you have sludge floating around, it can get clogged.

if you have 4wd replacing that oil pick up o ring is going to be a nightmare. much easier to test the screen first but yes there's a ton of videos on how to check and see if your oil pressure is low because of the pickup o'ring. since I have a steep driveway, I like the easy test of just backing up a steep incline and see if the oil pressure goes up. eaiser than adding more oil and then removing it. but both work.

if you have pressures and then it just drops to zero. that's normally sensor related. the o ring just allows it to suck some air alone with the oil lowering your pressure at idle a bit.