Oil light warning coming up. Dealor put a new oil sensor on, it lasted 2 weeks then oil sensor light warning coming on and not turning off with now a engine light and warning sounds. Had it towed to dealor. They said needs new oil pump but would not recommend for a car with this year and mileage. 08 Tahoe, 250k. No other previous issues other than a new transmission put in 3 years ago. Decided to have oil pump put in anyways ro see if it will run better. After installing dealor said running at 15-18 psi normal is 20psi..I pick up and drive home and driving normal speeds everything is fine no warning lights, steady at 20psi. When I slow down to 10mph or less the reading goes to 0, oil light and engine light come on to shut engine off. When start driving again normal speeds everything fine. No knocking sounds on engine and checked oil is fine. Please help with any advice or thoughts

Does the pressure go low on hard hole shot or around a fast corner? If so, the wall around the sump hole is open and the oil is easy to move out of the sump.

Pressure stays at steady 20psi until i slow down to 10mph or less than it dtops to 0 psi and oil light and engine light come on..reads low oil turn engine off. Will go back to normal once start driving over 10mph

Nearly zero PSI at idle is too low. Your 5.3 can tolerate lower pressures at idle, but I'm talking 10PSI, not zero. Personally, I'd look for 10-20 PSI at idle . . . but if your 250,000 mile engine hasn't been maintained well then 6-10PSI might be more reasonable on a new OEM style oil pump.

I'd take it back to the dealer and tell them to warrantee their work. If they said it needs a new oil pump to fix the problem, and the problem is not fixed, then they need to fix it. I'm guessing you put $1,500.00-$2,000.00 into that repair, right?

2008 wasn't a great year for the 5.3. They had AFM issues, oil consumption issues, and quality issues. If it were me, while they are in there I'd have them put in a high volume oil pump designed to run at factory pressure.

Maybe this is where you go back to them and illustrate how their fix did not fix it, and work a deal where they eat the labor and you buy a high-volume oil pump. Some dealers would work with you on something like this. Some would not. I can't tell which type your dealer is.

Operation CHARM: Car repair manuals for everyone.
Home >> Chevy Truck >> 2008 >> Tahoe 4WD V8-5.3L >> Repair and Diagnosis >> Specifications >> Pressure, Vacuum and Temperature Specifications >> Engine Oil Pressure

Engine Oil Pressure

Oil Pressure - Minimum Hot
1,000 engine RPM 6 psig (41 kPa)
2,000 engine RPM 18 psig (124 kPa)
4,000 engine RPM 24 psig (165 kPa)

Active Fuel Management Relief Valve - RPO LC9, LMG, LH6, L76
Oil Pressure 55-75 psig (379-517 kPa) Min-Max.

NOTE: As Measured at Oil Pressure Sensor Location.
pro multis · About Operation CHARM

So . . . I guess this is a case of finding out what pressure is actually being read, as opposed to what the friendly gauge is showing on the dash.

Operation CHARM: Car repair manuals for everyone.
Home >> Chevy Truck >> 2008 >> Tahoe 2WD V8-5.3L >> Repair and Diagnosis >> Engine, Cooling and Exhaust >> Engine >> Engine Lubrication >> Oil Level Sensor >> Locations

Oil Level Sensor: Locations

Powertrain Component Views

Right Rear Side of the Engine Components




1 - Ignition Coil 8
2 - Ignition Coil 6
3 - Ignition Coil 4
4 - Manifold Absolute Pressure (MAP) Sensor
5 - Throttle Body
6 - Ignition Coil 2
7 - Knock Sensor (KS) - 2
8 - Crankshaft Position (CKP) Sensor
9 - Oil Level Switch
10 - Starter
11 - Valve Lifter Oil Manifold (VLOM) Assembly (LY5/LMG/L76/LC9)
12 - Engine Oil Pressure (EOP) Sensor
pro multis · About Operation CHARM