2007 suburban dod/oil pressure light issue
10-18-2015, 10:36 PM
#21
No watery/foamy/abnormal oil, have pulled and cleaned the vlom filter, at cold idle the oressure when i checked it at vlom/opsu port was decent but still lower than galley plug as it warmed up the pressure at galley plug by oil filter was steady but opsu port started dropping.... Cut light on at about 3-4 psi abd went as low as 1-2psi but was within spec at galley plug..... I firmly belueve its dod related... The engine is quiet!!! Would an lm7 cam work in it???
10-18-2015, 10:37 PM
#22
TECH Veteran
iTrader: (36)
You might have isolated your problem via the diagnostics you have done already I read over that part and didn't realize it sorry. If you have oil pressure at the filter that verifies pump is operational. I'm not sure how you checked it but I have the gm puck that installs in place of the filter to get a reading. You should have the exact same pressure at the oil pressure sending unit as you read at the oil filter.
If not then it's one of 2 things the bypass valve in the pan is stuck open and bleeding all oil pressure into the pan. Or the second thing it could be if they put it back is directly underneath the oil pressure sending unit there is a oil filter screen designed to keep contaminates out of the DOD manifold assembly that screen could be plugged also. Either can cause your problem.
If not then it's one of 2 things the bypass valve in the pan is stuck open and bleeding all oil pressure into the pan. Or the second thing it could be if they put it back is directly underneath the oil pressure sending unit there is a oil filter screen designed to keep contaminates out of the DOD manifold assembly that screen could be plugged also. Either can cause your problem.
10-18-2015, 10:45 PM
#23
Bypass valve in pan would theoretically starve cam/crank bearings and if memory serves give unsteady reading.... As woukd a slightly worn bearing.... Or a clogged galley! Ive pulled her filter abd cleaned it twice..... Also if when you cone to a light while driving it, shut it down restart before kight changes the pressure will come up enough on guage to turn the light off but after few minutes or cruising at 45 it drops again..... Seriously thinking its either bad vlom or possibly lifter keaking on the dod "side" of the engine.... Leaning towards vlom but deleting dod would be best route
10-18-2015, 10:53 PM
#25
TECH Veteran
iTrader: (36)
00 - Camshaft
205 - Camshaft Sprocket
209 - Valve Lifter - Non-Active Fuel Management
219 - Valve Lifter - Active Fuel Management
407 - Oil Pump Screen
413 - Oil Pump
437 - Oil Filter
451 - Valve Lifter Oil Manifold
452 - Valve Lifter Oil Filter
455 - Active Fuel Management Oil Pressure Relief Valve
706 - Oil Pressure Sensor
Engine lubrication is supplied by a gerotor type oil pump assembly. The oil pump is mounted on the front of the engine block and driven directly by the crankshaft sprocket. The pump gears rotate and draw oil from the oil pan sump through a pick-up screen and pipe. The oil is pressurized as it passes through the pump and is sent through the engine block lower oil gallery. Contained within the oil pump assembly is a pressure relief valve that maintains oil pressure within a specified range.
Pressurized oil is directed through the engine block lower oil gallery to the full flow oil filter where harmful contaminants are removed. A bypass valve is incorporated into the oil filter, which permits oil flow in the event the filter becomes restricted. A second valve, the active fuel management oil pressure relief valve is incorporated into the oil pan. The active fuel management oil pressure relief valve limits oil pressure directed to the upper oil galleries and valve lifter oil manifold assembly to 379-517 kPa (55-75 psi) maximum. When main oil pressure exceeds 379 kPa (55 psi), the oil pressure relief valve exhausts excess oil to the sump.
Oil is then directed from the filter to the upper main oil galleries and the valve lifter oil manifold assembly. Oil from the left upper oil gallery is directed to the crankshaft and camshaft bearings. Oil that has entered both the upper main oil galleries also pressurizes the valve lifter assemblies and is then pumped through the pushrods to lubricate the valve rocker arms and valve stems. Oil returning to the pan is directed by the crankshaft oil deflector. The oil pressure sensor is located at the top rear of the engine.
With active fuel management activated, the engine control module (ECM) commands the 4 solenoids to open, directing oil through the engine block oil galleries to the intake and exhaust valve lifters for cylinders 1, 4, 6, and 7. Refer to Cylinder Deactivation (Active Fuel Management) System Description.
If you dont have oil pressure at the sending unit then the complete engine is starved of oil cam bearings rods and mains whole thing.
205 - Camshaft Sprocket
209 - Valve Lifter - Non-Active Fuel Management
219 - Valve Lifter - Active Fuel Management
407 - Oil Pump Screen
413 - Oil Pump
437 - Oil Filter
451 - Valve Lifter Oil Manifold
452 - Valve Lifter Oil Filter
455 - Active Fuel Management Oil Pressure Relief Valve
706 - Oil Pressure Sensor
Engine lubrication is supplied by a gerotor type oil pump assembly. The oil pump is mounted on the front of the engine block and driven directly by the crankshaft sprocket. The pump gears rotate and draw oil from the oil pan sump through a pick-up screen and pipe. The oil is pressurized as it passes through the pump and is sent through the engine block lower oil gallery. Contained within the oil pump assembly is a pressure relief valve that maintains oil pressure within a specified range.
Pressurized oil is directed through the engine block lower oil gallery to the full flow oil filter where harmful contaminants are removed. A bypass valve is incorporated into the oil filter, which permits oil flow in the event the filter becomes restricted. A second valve, the active fuel management oil pressure relief valve is incorporated into the oil pan. The active fuel management oil pressure relief valve limits oil pressure directed to the upper oil galleries and valve lifter oil manifold assembly to 379-517 kPa (55-75 psi) maximum. When main oil pressure exceeds 379 kPa (55 psi), the oil pressure relief valve exhausts excess oil to the sump.
Oil is then directed from the filter to the upper main oil galleries and the valve lifter oil manifold assembly. Oil from the left upper oil gallery is directed to the crankshaft and camshaft bearings. Oil that has entered both the upper main oil galleries also pressurizes the valve lifter assemblies and is then pumped through the pushrods to lubricate the valve rocker arms and valve stems. Oil returning to the pan is directed by the crankshaft oil deflector. The oil pressure sensor is located at the top rear of the engine.
With active fuel management activated, the engine control module (ECM) commands the 4 solenoids to open, directing oil through the engine block oil galleries to the intake and exhaust valve lifters for cylinders 1, 4, 6, and 7. Refer to Cylinder Deactivation (Active Fuel Management) System Description.
If you dont have oil pressure at the sending unit then the complete engine is starved of oil cam bearings rods and mains whole thing.
Last edited by 01WS6/tamu; 10-18-2015 at 11:01 PM.
10-18-2015, 11:02 PM
#26
As junked up as her filter screen thing has been im thinking theres some crap in the opsu passage then... Either way kinda over lustening to it if you know what i mean, so gonna get her **** fixed and get it over with..... And not have to listen to her again, about this anyway... But ive got two cans i can toss in it... Lq9 out of engine in my truck now, abd an lm7 cam out of a buddies engine he id getting ready to build, kinda thinking i want the lq9 for my yukon....
10-18-2015, 11:05 PM
#27
TECH Veteran
iTrader: (36)
I'm not trying to bother just give you the information to help you get it fixed.
It may be as simple as a stuck relief valve in the pan because you've already done half of the diagnostics by checking oil pressure at the sending unit and at the filter. All of the wordy stuff is directly from gm shop manual to help you through it and explain their function in the system as a whole. If the pressures don't match top to bottom dropping pan and changing the AFM relief valve is all you will need to do to fix it and move on.
Have a nice evening hope some of this helps you and I understand fully the situation you are sitting at in regards to working on a car that's not yours do it first hand myself same exact situation as yours.
It may be as simple as a stuck relief valve in the pan because you've already done half of the diagnostics by checking oil pressure at the sending unit and at the filter. All of the wordy stuff is directly from gm shop manual to help you through it and explain their function in the system as a whole. If the pressures don't match top to bottom dropping pan and changing the AFM relief valve is all you will need to do to fix it and move on.
Have a nice evening hope some of this helps you and I understand fully the situation you are sitting at in regards to working on a car that's not yours do it first hand myself same exact situation as yours.
Last edited by 01WS6/tamu; 10-18-2015 at 11:19 PM.
10-18-2015, 11:17 PM
#28
You arent bothering me!!! Lol she is!!! I appreciate your help, mitchell doesnt give you all of that, you get basic bs diags.... Ill try the relief valve in oan but i kinda want to get rod of her dod too.... To eliminate future issues, if nothing else!!! And plan to put pump in it while im there..... Abd check bearings to maje sure she hasnt f'd em up
01-12-2016, 09:58 PM
#29
Only taken 3 months(not that ive been overly worried about it) but i think i finally shut her and her light up.... Pulled her vlom filter and it was clogged again... pulled the filter out, at this point id rather just put another opsu in it, changed her oil and it felt like oil out of a diesel, or out of a newer car with gdi.... So i let it run for about 20 minutes drained oil again, still felt like oil out of an old 6.5 diesel so... put 4qts of oil and 2 qts of atf in it let it idle for another 10 minutes drained it and some nasty *** sludge crap out and put some pennzoil high mileage 5w30 in it and went and drove ig for about 20-30 minutes and oil pressure stayed about 40 at idle and went up with rpm.... Wanna say about 55-60psi.... Now shes complaining about losing brake fluid, her tires and traction light 
does it ever end
at least it comes out of the child support.....
does it ever end at least it comes out of the child support.....
02-06-2017, 09:22 PM
#30
So my ex dropped her burban off with me at work the other day, said she doesnt care what it cost, she wants it fixed, still using oil, but pressure is still up, pulled left valve cover and checked the pcv as per the tsb on oil consumption and found out the pcv system is leaking by, have pulled plugs trying to find a misfire none are oil fouled, plug wires on the right bank are oil saturated, right valve cover is leaking, as is the oil fill tube! She has been complaining about having to put brake fluid in it about once a month, pulled the master cylinder and found every bit of brake fluid she has lost, in the booster!! Also found out both ball joints, rf wheel bearing, left front upper rear control arm bushing, front and rear shocks, sway bar links and so far the left engine mount (right mount doesnt look too healthy) are all worn out and neding to be replaced! Finished the front syspension work today and started on rear shocks... tomorrow i will take care of the rest of it, hopwfully... she has trashed this poor truck!!!