'97 C1500, 5.7 Low/no oil pressure (indicated) at idle... FIXED

[HilltopRodShop]

Hey guys, I've seen good many posts about low oil pressure but not many listed a resolution. I hope this provides a quick reference.
-recently bought a '97 C1500, 5.7, 5 speed, 3.42 POSI.
-low oil pressure at idle (actually showing about zero), triggering "check gauges" light
-previous owner recently installed "aftermarket" oil pressure switch
-removed high filtering Bosch oil filter, installed AC Delco oil filter, NO CHANGE AT ALL
-installed new GM Genuine Parts 19244500 Engine Oil Pressure Sensor
-PROBLEM RESOLVED
-truck now has no less than 18 lbs at hot extended idle such as waiting thru multiple red lights in 85 degree weather.

Thanks much, G

 

[Schurkey]

So the oil pressure sensor was the "Fix"?

 

[HilltopRodShop]

So the oil pressure sensor was the "Fix"?

Yes sir, the AC Delco, made in Mexico switch fixed it. I want to make some comment about certain countries are better at making viruses than oil pressure switches but I won't...this is in reference to the other new switch I took off. It probably didn't have 1,000 miles on it.

 

[someotherguy]

Surprised you didn't find other threads pointing at the sensor. It's a somewhat common failure. Even the OEM ones, once they get old, will fail but usually go intermittent before total failure. You'll remove the harness and find they have leaked oil through to the socket.

When there's no unusual engine noises associated with "zero" oil pressure, you can just about always bet on a failed sender. Glad you got it sorted out, and while GM/AC Delco has cheaped out manufacture of a lot of their stuff for many years now, I'd still trust their sensors more than brand X.

Richard

 

[Komet]

Oil pressure sensors die in all of my vehicles, I guess I should be fortunate my curse is easily solved. I've had them work fine but drip one drop of oil per second. I've had them go to zero psi at an idle (no leak on that one but did let oil into the contacts so it was starting to go). I've had them max out the gauge but not leak.

 

[L31MaxExpress]

Oil pressure sensors die in all of my vehicles, I guess I should be fortunate my curse is easily solved. I've had them work fine but drip one drop of oil per second. I've had them go to zero psi at an idle (no leak on that one but did let oil into the contacts so it was starting to go). I've had them max out the gauge but not leak.

I have never had one fail electrically (well one but it broke in half and started pouring out oil), but I have had several leak and one was a massive leak. Luckily I shut the engine off because whem the sensor failed, the dash gauge went to zero at the same time the oil geyser started flowing out of the two piece sensor. I had one fail on a LT1, fill the PCM with oil, and fried the PCM. The sending unit was wired directly to the PCM and the wire and weather pack connectors make a perfect oil capillary tube to push oil right into the PCM. That one took me a minute of thinking to figure out how a PCM could possibly get what seemed like a quart of used motor oil inside of it.

 

[Schurkey]

I've never had that style of sensor fail. I believe it's possible, just never had that experience.

The old '88--'89 style oil pressure sending units, on the other hand...
www.automotiveforums.com/vbulletin/showthread.php?t=1136624

Oil Pressure Sending Unit--TBI V-8 dash gauge - Automotive Forums .com Car Chat

Oil Pressure Sending Unit--TBI V-8 dash gauge C/K

www.automotiveforums.com

 

[HilltopRodShop]

Hey guys, I've seen good many posts about low oil pressure but not many listed a resolution. I hope this provides a quick reference.
-recently bought a '97 C1500, 5.7, 5 speed, 3.42 POSI.
-low oil pressure at idle (actually showing about zero), triggering "check gauges" light
-previous owner recently installed "aftermarket" oil pressure switch
-removed high filtering Bosch oil filter, installed AC Delco oil filter, NO CHANGE AT ALL
-installed new GM Genuine Parts 19244500 Engine Oil Pressure Sensor
-PROBLEM RESOLVED
-truck now has no less than 18 lbs at hot extended idle such as waiting thru multiple red lights in 85 degree weather.

Thanks much, G

For my post above, I was just trying to convey that if you have an oil pressure issue...and you replace the sensor with a sensor other than an AC Delco sensor, you may be doing the job twice. I have a brand new sensor "aftermarket" sitting on my work bench that confirms this. I was just trying to save someone else the trouble. I see many posts on forums that lists issues but no final resolve. This is the first time I posted...I tried to list the issue, what didn't fix it and what actually did fix it along with the part number. I hope it will help someone out there. Thanks, G