Oil pressure gauge reading zero, sometimes.

[docmarten]

The other night, it was raining like mad and large pools of standing water were every where. After going through one of these puddles, (it was unavoidable) my oil pressure gauge dropped to zero. I checked the oil after coming out of the movie theatre and there was plenty. On the way home, the gauge started creeping back up to about 20 psi. Since that night, the oil gauge reads zero when I start the car, then after about nine miles of driving, it creeps up to about 40+ psi. I just checked the oil again and the level is fine.

My question: does this sound like a wet connection? If so, which connection and should I look into replacing anything?

Thanks!!

[00Beast]

Sounds like the oil pressure sensor. I'd inspect it and the wiring, and if it appears fine, replace the sensor with an AC Delco.

More info: http://www.pontiacbonnevilleclub.com/fo ... 53&t=17496

[smittyingr]

You would assume this would be a connection issue because of the puddle but I would want to know for sure. I just went through some oil pressure issues.

Do you hear the top end of the engine getting noisey when your gauge shows 0?

Autozone will loan a tool a mechanical oil pressure gauge that you can use to check it for sure. The oil sending unit is on the back side of the engine sticking out of the oil filter adapter. Take the sending unit out and put in the mechanical gauge in the place of it and start the car and see what it says. However 20 psi is to low. I belive you should be at 40 psi at idle and run up to 60 or so with some throttle. If you kneed more info on how to install and use that tool let me know and I can put together a step by step for you.

Also you can get an aerosol can of electrical connection cleaner/dryer and spray the sender and the pigtail first if you want to and see what happens.

This is my thoughts but mabey someone else can back me up or put in their thoughts.

[docmarten]

You would assume this would be a connection issue because of the puddle but I would want to know for sure. I just went through some oil pressure issues.

Do you hear the top end of the engine getting noisey when your gauge shows 0?

Regardless of what the gauge reads, the engine does not sound any different than normal.

This afternoon when I left the yoyo shop, the gauge showed zero upon start up but within one mile the needle started creeping up and was showing full pressure within two miles.

I will inspect the sending unit and wires as soon as possible.

[rustyroger]

If you drove the car 9 miles with no oil pressure you would surely have issues by now.

I agree with the other posts, I think the sender is playing up.
You might want to think about replacing the electric gauge with a mechanical one for peace of mind.

Roger.

[00Beast]

The PCM also reads the sensor, so replacing with a mechanical sensor is not really a viable option. Replace the sensor and inspect the wiring.

[bc21]

mine did the same thing bounced back and forth. i replaced the oil pressure sensor. It has been normal ever since.

[docmarten]

This past weekend was quite warm here in the mid-Atlantic region, so warm that I was riding my sidecar rig around instead of using the car, but, I checked the OPS as good as I could and everything looked fine. I used the car today and the gauge is working fine. Upon start-up it read 50-60 psi as it always did before the puddle incident last week. I suspect that something got wet when I went through the puddle and it finally dried out. Next oil change, I will inspect the wiring more closely and go from there.

Thank you all for the advice.

[packratjohn]

Have a 92 with an OPS that will max out at times. Other times it's in normal range. No change in performance. Sensor? Where is it located? I can change it, but would like suggestions or feedback. Thanks folks.