after starting my truck, I had been in a store for app. 30 min. When I pulled away the oil preasure dropped to 0 and the light warning came on. I checked the oil, it was full. When I re-started it, the gauge climbed, 15 seconds later it was back at 0. I did this 6 times or so and it then stayed up. I drove 4.5 hours it was fine. the next day on start up it did the same but was fine on the third start. Drove for 2.5 hours no problem.
My thoughts are it is electrical. Any thoughts?
James

 

How cold was it outside? What weight of oil are you using? The reason I ask is that the same thing happened to me at -40. I still had 15w40 in the truck at the time.If you turn on and off your ignition key you might find a code that indicates a low oil pressure condition.

 

engine was operating temp the first time it happened, second time it was -8'C outside.

James

 

sounds like the sender may be going bad.... I'd take it in ASAP to have it checked out just to be on the safe side.

 

I would put a mechanical gauge on it to make sure. If it is still under warranty (<100k miles) I would also take it in to avoid being blamed for driving it while you knew the oil pressure was saying zero.

 

There is probably nothing wrong with the oil system, just something in the sending system. But a good point was made about getting it in to the dealer.

 

My 1999 has the same problem - diagnosed - oil pressure sensor - $280 - too steep for me! Works most of the time now - keeps getting better and better.