Today this is not what you want to see on the highway at 65mph...


History- Replaced the oil pressure sensor with Delco one 16 months ago...
due to high erroneous readings. After replacement it read around 44psi until
about 3 months ago it started reading 129 psi as normal highs again.
Figuring it needs another oil pressure sender, I left it until today, until oil light went on & oil pressure reading down to or at zero..Got my full attention Now!!!

Ok so this is what is currently doing.....
Reads 129 psi until revs hit around or above 2200 rpm...
then it drops to zero and left oil light comes on....(zero psi)

Once the revs drop back down 800 rpm the oil light goes off and returns to 129 psi.

Bought another sending unit this time going to try a Standard sensor.

Only this time I am going to get a pressure gauge on to see where it is really at first. Then install the new sensor and hope 4 the best.

The only thing that has me nervous is that the engine seems to have good pressure at idle but drops right off at higher hwy rpms...based on the computer....

Thoughts greatly appreciated..cause I am thinking this motor may be on the way out some how...

Will know more as soon as I can get it in the lift...working on that now..
In the meantime maybe it is best I dont drive it..??

With this computer DIC can it be by passed somehow & get a real pressure ga. installed with out lights on or dings going off?

I'm in the process right now of changing my sensor on my new SSEi because it showed an immediate peg at 120 on start-up. Mine has always stayed there since I got it a few weeks back. The only time I've ever seen such was a bad sensor on my GP. I have my fingers crossed it'* not the gauge cluster as some suggested.

I'd think you could hook an external gauge up with the line connected in place of the sensor. Not sure about keeping the dings from going off though while you check it. I'm sure one of the techs on here might know about that part so I'll watch to see what they say too.

Buy an AC Delco. I've been seeing too many OP sensors going these days. Sometimes you get what you pay for. Either they go erratic like yours, or the diaphragm breaks leaking oil everywhere.

I also forgot to ask if from 129 psi to absolute zero could indicate connection problem?
Is there a replacement connector available for the sending unit that could be utilized?

Not sure what an open connection would do. It may tell the gauge to go high or do nothing at all. All depends on how its designed.

Put a mechanical gauge on it and verify the oil pressure. Any other troubleshooting is moot until the pressure is verified.

Are you asking if you can keep any warnings/dings from going off while testing the pressure, or are you considering installing a mechanical gauge permanently?
A while back I considered installing one permanently, all you'd need is a NPT Tee, and you could run a good mechanical gauge into the inside of the car, I just was weary of having hot oil running inside the car, but I suppose it is fairly safe, as a lot of modders, and racers have them.

Once you verify if the pressure is actually dropping or not, if it is not actually dropping then you could wiggle the wires around a little while it is running, and see if the gauge changes, just be careful while reaching in there with it running.
Also I agree with Mike, I'd go with an AC Delco sensor again, I had bad luck with anything other than the OE AC Delco one.

Here is the Tee I was going to get.

I was thinking about if this next sensor goes sideways, to eliminate it by hopefully installing a real pres ga. and not have the oil light or dings on ...after installing it...

Art, I just took mine off the jacks. My oil sender was soaked with P/* fluid from a leaking line and covered in crap. I pulled the plug, shot it out really well with contact cleaner, shot a small shot of dielectric grease in the connector and reinstalled. Works fine so far so I held off changing that booger for right now since it looks like a pain. The leaking P/* pressure line that soaked it..well... that looks like another day on jacks with my old azz on my back...... :(

Thanks Stephen, that gives me an idea to try to clean the connector with contact spray & then start engine... to give me a hint ...if it is electrical....

It is possible to "fool" the car with the OP. The OP sensor is a variable resistor. Depending on how its designed, the more pressure, the more resistance in the circuit.

1. Disconnect the electrical connector from the OP sensor.
2. Connect a multimeter to the OP sensor
3. Start the engine, note how many ohms are displayed on the DVM
4. Purchase equal value resistor from Radio Shack and install it onto the wiring side of the circuit(the plug you disconnected). Now your gauge should show the same PSI no matter what the engine is doing.