Low oil pressure after rebuild. 2011 Suburban 1500 LT

[TCrutisonJr]

I am on the back end of my first rebuilt engine. I have a daily 2011 suburban 1500 LT 4WD. I did a DOD & VVT delete because my lifter took out my crank lol. I have a new OEM GM crank and a Truck Norris cam now. After the engine warms up i get low oil pressure. The Oil Pressure sensor was bad but i replaced it this morning. I have a new camshaft retainer plate and i have not plugged the oil bypass in the oil pan. I have a new standard oil pump M365.

Do i need to plug the bypass?
what can i plug it with?
Do i need a high volume pump?
Is their anything in the tune settings that could effect oil pressure?

MOST IMPORTANLY, is there anything that i could be over looking or not considering?

I really appreciate everything it takes to make this possible ... you people are cool

[edcmat-l1]

Nothing "in the tune" affects oil pressure.

What's the cold pressure? What's the hot pressure?

Did you forget the dumbell in the back of the block? Very common for first timers.

[TCrutisonJr]

Cold is right at 40 or literally just below. hot gets pretty low maybe 10 or 15. I have not replaced the dumbbell. I googled it and it doesn't seem too hard to get to. Could it really be that small? Almost makes me want to tear it back down and clean again.

[TheMechanic]

10 psi per 1,000 rpm has been my standard for decades.
Hot.
Cold doesn't really matter as long as it minimums the 10 and max's 80 on a stock filter. NON dry sump

[TCrutisonJr]

So everything is okay?? As I Rev it the oil will go up some, but how do i keep it in operating zone?

[TheMechanic]

If you have the 10 per 1K you are good. If not, you're not.
One more thing to check is the filter in the oil pressure sending unit hole. It may have debris from the engine failure. It is more often missed than even the dumbell.

edit:
It is technically not a filter. It is a screen.

[edcmat-l1]

10-15 is lower than I'm comfortable with.

[TCrutisonJr]

The oil pressure sensor is brand new i replaced it this morning. the Valley cover i have seems not to fit the filter, so its currently not there. I had low oil issues and that started this whole journey for my sanity i would love to not see that light for a few years.

[blindsquirrel]

The bypass in the pan should only cap the pressure to 55psi max - at least that's the spec in the service manual. It could be stuck open though if there was enough debris to take out a freakin' crankshaft.

[blindsquirrel]

The filter/screen at the sensor is to protect the VLOM, not the sensor, so with a non-DOD valley cover there is no screen.

Are you checking pressure with the sensor's reported values in the scanner or checking it properly with a real proper mechanical gauge?

[TheMechanic]

10-15 is lower than I'm comfortable with.

I stand corrected.
Screenshot 2024-03-14 172612.png

[LS ROB]

Have you checked the Oil pump to pickup tube o-ring?

I used one of these:

https://www.summitracing.com/parts/s...caAsFXEALw_wcB

I do think I had to use a file in order to get the fitment the way I wanted.

[GHuggins]

I may have over looked it, but did you replace the vlom with a regular plate? Are the oil passages for the DOD lifters plugged in the block via the metal plugs you hammer in or with the O-rings via the non dod plate? Usually low oil pressure after a delete is because the vlom was left in place.

[TCrutisonJr]

yeah, there was alot metal shavings.. i had a "lovely Individual" tell me to disconnect the fuel injector to one of the DOD cylinders to help with a misfire... looking back i think i needed the DOD delete.

i have replaced the DOD valley cover with a non DOD cover. The cover has o rings in it to block off the tops of the oil passages.

I bought a oil pump that came with a pickup tube. The Pump came with 2 O rings and the pickup came with one installed (Red). I believe its the right sized one but I'm open to being corrected "M365 395S"

[GHuggins]

If you had that much metal and the vlom was replaced with a non one on top of getting a new thrust plate then most likely it's worn bearings. Oil pressure is read straight from the cam bearings, but rods and mains will affect it. When a cam is installed if the bearings are nicked or worn combined with it being possible for a slightly different diameter on the cam journal then that will cause lower pressure. Cam bearings aren't easy to do. They've really only recently came out with tools to press them in right without deforming them and one of them has to be done from the back side on the ls's block. It's actually the second one in from the rear funny enough. If this is the problem the motor will need to come back out. Check the other possibilities first.... I was hoping you just left the vlom on as it's got an oil passage in it that a lot of people don't know about that will allow oil pressure to bleed off via the oil pressure chamber to the solenoid valves that are naturally open. Guess it's possible the O-rings didn't seat good or one blew out. You could check that just to be sure.

[edcmat-l1]

Yeah depending if the block was thoroughly cleaned and cam bearings replaced, it probably needs to come back out. No easy fix for this one. Dumbbell needs to come out, freeze plug at the front of that galley needs to come out, cam bearings, block needs to be put in a wash machine, and the galleys need a barrel brush run through all of them followed by a good soap and water hand wash. Then put cam bearings in it. Can't do that before all the cleaning is done and there is NO CHANCE of any metal in it anywhere.

Lack of attention to detail particularly cleaning is the biggest engine building mistake you can make. I'm a freak about it.

If an engine ISN'T thoroughly cleaned abrasives will quickly destroy the bearings. If the old cam bearings haven't been replaced, they will be your low oil pressure leak. On the other hand, if the engine is near sterile you can run one with very low oil pressure at no load and have virtually no engine damage if you catch it in time.

[TCrutisonJr]

I replaced the main and rod bearings and i cleaned it really good with exception to the dumbbell to freeze plug galley. I'm currently in the re-tear down faze now. Is the standard volume pump okay after DOD delete?

[5FDP]

Yes, a standard pump is more than fine.

[blindsquirrel]

Block the bypass in the pan if it's coming apart, it's needed only with the original high volume DOD pump.

[edcmat-l1]

The galley with the freeze plug at the front and dumbell at the back is the main oil galley.