GM 5.3: No oil pressure after oil change

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Jan 11, 2007
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2008 Suburban 5.3, 154k. Changed the oil tonight. When I went to start it after refill, the gauge did not show any oil pressure. After about 7 seconds or so (felt like years), I knew something was wrong and turned the truck off. I tried it again quickly and still no pressure. I wondered if I had a filter issue so I removed the filter and put another on. No change.

It has oil and it’s apparently not a filter issue. Has the pump failed? Has the oil pressure sensor failed? All other gauges work fine. Any idea why draining the pan would cause something to change?
 
I do not know anything about about GM 5.3 but have owned cars where oil pressure sensor is in filter housing. Did you knock off sensor plug or damage sensor or wire possibly when changing out filter?
 
You will need to perform a oil pressure test to confirm, check the wiring.

What filter did you use to begin with?
 
Wix was original filter. Came off looking just fine. ACDelco on now.

Prime idea makes some sense. Changed perpendicular on moderate grade driveway to facilitate draining. Never had a problem doing it this way before but I wonder if this is a prime or pick up issue.
 
I do not have a direct suggestion but do want to remind that GM has clear flood mode. Accelerator pedal to the floor and crank the starter will keep turning the engine over without firing.

Just wanted to mention if needed.
 
More than likely a failed oil pressure sensor, If the lifters are quiet.....You have oil pressure.
Thanks. Any idea why an oil change would prompt this? It would be a heck of a coincidence if the oil change wasn’t the impetus for the sensor failure…
 
Thanks. Any idea why an oil change would prompt this? It would be a heck of a coincidence if the oil change wasn’t the impetus for the sensor failure…
It is a coincidence most likely. Yes, the timing is curious, but stranger things have happened.

Sometimes a spoon is just a spoon…on the other hand, just because someone is paranoid doesn’t mean there aren’t others out to get him.
 
GM Ls engines are known for the o ring on the oil pump pickup tube shrinking and allowing the pump to suck air.
If this is the case, usually a quick rev of the engine will allow it to pick up oil pressure.
 
If that lost “prime“ the upper end of the engine would be loud and clacking away, you’d know quickly.
 
There is a little screen in the oil galley that feeds the VLOM that's designed to keep junk from entering the AFM solenoids.

This galley also feeds the oil pressure sensor. If the screen gets clogged with gunk, it prevents oil from reaching the sensor and will report as no oil pressure. The screen is located right under the oil pressure sensor. Unscrew the sensor, pop out the screen, clean with a little brake clean and some air (or just replace), and reinstall.

Search for "LS oil screen" on YouTube. Many videos on the issue with walk-thrus on how to remove the screen.
 
Just another possibility... the clusters/dash are notorious for being terrible on these. I'd say I see one a day in the shop with the odometer, speedometer, and oil pressure not working. Good Ole GM.
 
There is a little screen in the oil galley that feeds the VLOM that's designed to keep junk from entering the AFM solenoids.

This galley also feeds the oil pressure sensor. If the screen gets clogged with gunk, it prevents oil from reaching the sensor and will report as no oil pressure. The screen is located right under the oil pressure sensor. Unscrew the sensor, pop out the screen, clean with a little brake clean and some air (or just replace), and reinstall.

Search for "LS oil screen" on YouTube. Many videos on the issue with walk-thrus on how to remove the screen.
This is where I would start and most likely finish.
 
More than likely a failed oil pressure sensor, If the lifters are quiet.....You have oil pressure.
This exactly.

If when started and the engine sounds normal, probably a false reading. The original 5.3 in my Tahoe did this once. Was driving down the thruway and the oil pressure gauge said 0. Engine sounded fine. It was a bad stepper in the cluster.

LS will sound like death without oil pressure.
 
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