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2002 GMC Envoy oil pressure dropped, won’t start

2002 Gmc envoy oil pressure dropped stop engine light came on. Truck stalled and wouldn’t start up. What can be the problem

No engine oil and you seized the engine . Did you check the oil to see if it has any ?


How long was it between when the light came on and the engine stalled?

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On some cars a low oil pressure signal prevents the fuel pump from running. It could be a bad OP sensor - or actual low oil pressure for some reason.

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The Trailblazer/Envoy platform uses a pressure switch to determine if oil pressure is present or not. Although there is a gauge, it is fake information from the computer, projecting pressure value based on RPM reading and knowing baseline was enough to trip the switch.

When the computer sees 0 oil pressure, it lights up the check gauge lamp or, if you have a DIC, will display the stop engine message.

Your problem could just be a failing pressure switch. Or, the problem may be real and you have no oil pressure due to insufficient oil in engine, pump failure or obstruction of the oil flow inside the engine.

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A few seconds I was at a street light.

This GMC isn’t set up that way

This could be anything from a dead battery to a failed fuel pump. A description of the no-start condition is necessary.

What a joke, to have a fake oil pressure gauge just to save a few pennies in manufacturing costs! If all I wanted was an idiot light to tell me that the engine has no oil pressure, then I wouldn’t pay extra for a full instrumentation dash, and if I did, I’d expect the oil pressure gauge, battery voltage gauge, etc. to be displaying the actual information–not some made-up value of what it “should” be.

Are all GM vehicles this way? I have driven several Chevrolet Express cargo vans, and a Chevrolet Astro van as work trucks, and I currently own a 2000 Chevrolet Silverado. All of these were equipped with battery voltage and oil pressure gauges. Are the oil pressure gauges in GM trucks fake too?

A lot of Fords also typically have a “fake” engine oil pressure gauge

If pressure is within specs, the needle will always be right in the middle . . .

There’s often no choice . . .

you either buy the car with the gauges, “fake” or not

. . . or you leave and buy a different vehicle

No . . . they use real engine oil pressure sensors, not engine oil pressure switches

There is a difference between an engine oil pressure sensor and a switch

The Fords have a simple engine oil pressure switch, yet the cluster has what appears to be a gauge. yet electrically it doesn’t function as a true gauge.

Those older GM work trucks you mentioned . . . I know for a fact that the engine oil pressure gauge will definitely be on the low side if you do in fact have rather low engine oil pressure, say 8psi, enough to keep the red oil pressure warning from turning on, but not exactly stellar, either. Rev the engine or cruise at 2500rpm and they’ll display a much higher reading. So what you see is the truth

And the battery voltage gauge is also telling you the truth. I’ve verified this with my multimeter countless times. On those GM work trucks, at least

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This is true for the 4.2L I6 engine. From what I can tell, the V8’s in the Trailvoys and the full size trucks used an actual oil pressure sensor.

I can personally say you are correct . . . because I’ve replaced a few engine oil pressure sensors on those trucks you mentioned

Op, suggest u obtain a oil pressure test using shop gauge during cranking. Also a basic obdii code read. Post the results here if u need more ideas.

Paying for an oil pressure test on an engine that does not start will be a waste of time and money, need to focus on the no-start problem.
It is normal to have a loss of oil pressure when an engine stalls.

The V8 wasn’t available in 2002. It first became an option in 2003 and only in the XL version.