I have not posted in a while but I will say right off the bat some of you will think I am crazy for running the truck.

Anyways, a week or so ago I had to remove my Magnacharger to do some maintenance (intercooler fitting leaking) and also add an RDS phenolic spacer. Once back on, I found the in dash oil pressure gage would read 0 PSI and the DIC would read "Low Oil Pressure" on cold start. I have had an oil pump pressure relief spring stick on my old 5.3 so I know the risks of running with this warning. After checking a few things I decided to go for broke and run the engine again. After a short while, the gage went back to normal and the DIC message went away. I have been driving the truck like this for days without any engine noises and the truck runs as it should. In fact today, I drove 50 miles round trip without an issue. Once the gage comes back to life the pressure it where it should be. I changed the oil the very next day after the issue came up and nothing was out of the ordinary. It seems as though once I hit 1ge will immediately show pressure upon restart. 800 rpm or so the gage will work and stay working. I can even shut it down for a while and the gage will work immediately upon restart.

Has anyone had this happen before? I am planning on checking the pressure with a mechanical gage to verify. My AutoCal shows 0.5 V when this happens which converts to 13 PSI using the 5V = 130 PSI specification.

 

Sensor on the back of the motor is probably going out.

 

I was leaning toward that is I could have hit it during the reinstall. Now the question....has anyone changed this sensor WITHOUT removing the MagnaCharger. My idea was to undo the transmission mount and jack the rear up to tilt the engine forward. This may give a bit of room to work. With the addition of the phenolic spacer (1/2" thick) the already tight area is now even tighter.

 

my gauge has been bouncing back and forth for over a year now. just the way its been acting i knew it was the gauge or the sensor...i had similar issues with my gas gauge, speedo and water temp also.. i have a maggie also and have been hesitant to replace the sensor

 

You'll be removing the Maggie.

 

These gauge clusters are notorious for working sometimes and then they quit working. We rebuild them all the time.