Oil Pressure Sensor

[backroad101]

So I replaced my Oil Pressure Sensor back in March. Symptoms were that if i drove the truck past a certain length of time (usually highway), when I came to a stop at a light or something, my Oil Pressure gauge would start to go nuts. Sometimes it was only if i was sitting still, foot on brake and turning the steering wheel a little. Sometimes it is me just sitting with foot on brake. If I lift off the brake it is fine. Also, day to day on my short trip to work (approx 7-10 miles) the problem does not happen.

After I replaced the sensor back in March the issue went away. Now it is back, same symptoms. Possible it's just a bad sensor or do you think there is a strain somewhere causing it? Could something in the steering be affecting the reading? Truck runs fine otherwise


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[Explorin94]

Dump it and put an actual guage for the oil pressure. The "guage" in the dash is only a switch as is the sender that you recently put on. Your problem probably lies in the dash portion and not the actual sender itself.

 

[Earl43P]

I'm gonna say you have a low idle.

You might also have a vacuum leak causing the low idle since pressing the brake pedal uses vacuum.
Intake gaskets are typical problems on 4.0s, but check the PCV too.
http://www.therangerstation.com/Magazine/Summer2003/VacuumLeaks.htm

Might try cleaning the IAC too.

Then disconnect the battery and turn on/off the headlamps. Reconnect battery and let it idle 4 minutes in each of these conditions:
Park
Park with AC on
D with Brake or PB set , I forget which
and D with AC

 

[ElleShooTiger]

The "sensor" is a simple pressure switch, not a real sensor. All it does is provide ground once a certain oil pressure is reached. The gauge just jumps to the center when the switch grounds itself.

You should be able to troubleshoot the sender with a simple multimeter. Remove the single wire lead and check that the sensor shows ground when the engine is running. Also, if the wire's connector is oily or loose, it can cause a bad connection and a bouncing gauge, crimp the connector a bit so its tight when you put it on the sensor.

Last year, I downshifted and revved the 4.0 hard, next thing I knew, oil was blowing out the back of the truck! Turned out that the oil pressure went up so fast that it blew the 250k mile sensor apart! It was NOT a fun 2 mile drive home, I was able to stop and buy more oil to keep it from running dry until I got home, but it leaked out a good quart every minute it was running, what a mess it made underneath.