I have a 2013 tahoe that I bought in October of 2024. When I got it I wasn't having any issues. Took it for an oil change and was told there was a rear main seal leak. They told me I could manage that by topping off the oil every so often when needed until I could get it fixed. Finally got someone out to fix it but they told me it wasn't the rear main seal but it was the valve cover gaskets instead. got those changed out. Now had some others issues come out but got them taken care but now I have no oil pressure. We got the oil pressure sensor replaced and still having issues. There's no knocking noises or overheating or anything. It'll be fine driving 5 or so miles then the oil pressure just drops to zero. We know its not the rear main seal because my oil level is holding at the same level. there's no more leaking. Ive read lists of causes but I can't afford to keep guessing what the issue could be.
2013 Chevy Tahoe low oil pressure
- Thread starter Katie0402
- Start date
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Dustin Jackson
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@Katie0402 The oil pressure was only a concern after you tried to fix the oil leak? I wonder if the wiring to the oil pressure sensor was damaged. You could connect a mechanical oil pressure gauge to verify the oil pressure is ok and then try to hunt down why the sensor is reading that way
could be a few things if the dash gauge says zero but the engine has pressure (wire / sensor / screen plugged)
First step is to verify the dash gauge is correct, per the post above, mechanical gauge to verify the dash. Also, was the old sensor bad? They can be tested.
First step is to verify the dash gauge is correct, per the post above, mechanical gauge to verify the dash. Also, was the old sensor bad? They can be tested.
Joseph Garcia
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Welcome to the Forum from NH.
Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.
I hope that you will become a participating member in the Forum's discussions.
Pics of the truck, please.
You are already receiving sage advice from the knowledgeable folks on this Forum.
As the folks stated above, get yourself a mechanical pressure gauge from Harbor Freight with the correct fittings and establish what your REAL oil pressure is. Once that is complete, we can assist you on the next troubleshooting and/or solution steps.
Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.
I hope that you will become a participating member in the Forum's discussions.
Pics of the truck, please.
You are already receiving sage advice from the knowledgeable folks on this Forum.
As the folks stated above, get yourself a mechanical pressure gauge from Harbor Freight with the correct fittings and establish what your REAL oil pressure is. Once that is complete, we can assist you on the next troubleshooting and/or solution steps.
We did not have the sensor checked. I was told by a mechanic to just change the sensor first. But after taking the old one out and putting the new one on, we discovered another old one tucked back in an open space which had us thinking it had already been replaced once before. The guy who changed it out this this time did say the little screen with the sensor or whatever felt "gritty" but put it back on and didn't say anything about needing to replace it.
Also another question, if the oil pressure is fine when first started, then drops after driving, how would that work using a gauge? I haven't driven the Tahoe in weeks. would I have to try driving it again to see if the oil pressure drops again then check with a gauge or would we just check without driving first?
Charlie207
Full Access Member
The dash gauge is a "dummy" gauge, and not directly sourcing its signal from the oil pressure sender on top of the engine (in the back). The signal is routed through sender, to the PCM/ECU, then to the dash.
A mechanical gauge that's attached to the engine will give an instant/real-time measurement of the oil pressure. You'd want to observe the pressure when cold (at startup), and then after driving around to allow the oil to warm up to operating temps.
For pure speculation, oil pressure issues in these engines are almost always related to the oil pickup tube o-ring, which seals the pickup tube in the oil pan to the oil pump. It's a cheap part, but requires a bit of labor to access and replace.
EDIT: Another thing to try is to disable the AFM/DoD system (cylinder deactivation) by driving around in Manual Mode - Gear 5. This will leave the engine in V8 mode, and MAYBE prevent some sort of pressure loss occuring when the AFM/DoD system is switching to V4 mode to save fuel.
Unbelievable. The guy said the little screen felt gritty and he put it back in? So in other words that screen was partially plugged. That will definitely give you a lower oil pressure reading than what you really have. I would not take it back to that shop!
I would remove that sending unit, and the partially plugged/covered in grit screen.... Only replace with a genuine GM or AC Delco sending unit. Get the one that comes with the screen.
And look online for a oil pressure sending unit relocation kit. Comes with a steel braided hose, and you can use a zip tie to tie it off on the firewall. Not only does that make future changes a 5-minute job, but you can readily swap out in mechanical oil pressure gauge to test the pressures.
Plan on doing the oil pick up tube o-ring. It's not only a factor of mileage, but over time as well. If you're not deleting the AFM, replace the oil pressure relief valve in the oil pan. It's right around a $20 part. And definitely turn off the AFM, preferably in the ECM with a tuner, or one of the inexpensive devices that simply plugs into the OBD2 port.
I would remove that sending unit, and the partially plugged/covered in grit screen.... Only replace with a genuine GM or AC Delco sending unit. Get the one that comes with the screen.
And look online for a oil pressure sending unit relocation kit. Comes with a steel braided hose, and you can use a zip tie to tie it off on the firewall. Not only does that make future changes a 5-minute job, but you can readily swap out in mechanical oil pressure gauge to test the pressures.
Plan on doing the oil pick up tube o-ring. It's not only a factor of mileage, but over time as well. If you're not deleting the AFM, replace the oil pressure relief valve in the oil pan. It's right around a $20 part. And definitely turn off the AFM, preferably in the ECM with a tuner, or one of the inexpensive devices that simply plugs into the OBD2 port.
