I have a 95 F250 7.3. I'm getting a low oil pressure reading from my gauge in the dash. I know these gauges have been known to be unreliable but it's starting to concern me. I have plenty of oil in the truck but it still reads low. Does the gauge read low pressure oil or high-pressure oil?

just wondering what the steps are to start testing and getting a better idea of what's actually going on

 

 

I'd try a new sending unit, as these engines won't run without oil pressure to fire the injectors. I was driving my 97 one day, and looked down at the gauges, and saw the oil pressure was reading 0. I about soiled my drawers, then remembered that they won't run without oil pressure. A new sending unit cured my problem.

 

It reads low-pressure oil, but it's just a dummy indicator. It only operates in two positions. When there's zero pressure, it reads all the way left. When there's "enough" (something like 7 PSI) pressure, it's supposed to read in the middle. So if it's responding at all, then it's working. If it's not, then there's something wrong with either the gauge head or the sender.

Remember, if you didn't have at least some output of the lube oil pump, your engine wouldn't run.

 

Yeah it's reading all the way to the left now. Used to reason the middle.

So I should start with a new sender? It's threaded into the HPOP reservoir right?

 

Does it move at all engine-running vs. engine-off?

 

When I got the truck it read right in the middle. Recently it's read between all the way left and the N of Normal. Just today it started reading pretty much all the way to the left like in the picture. It does slowly fluctuate closer to the N but still doesn't pass it.

 

I would by a new sender Or check the wiring....1995 FORD F SUPER DUTY 7.3L V8 DIESEL Turbocharged Oil Pressure Sender / Switch | RockAuto

 

Going to grab a new sender now. Is there anything I need to do before installing the new one? When I pull the old one is pressurized oil gonna blast me?

 

yes oil will blast you, if the engine is running


after a few seconds pressure is gone when you shut off the engine

 

Ok cool thanks that's what I figured. Hopefully this is all it was not an oil pump 🙄

 

Again, if the engine's running, you at least have SOME oil pump pressure. And if the pump is producing lower pressure than before, it won't show up on the "gauge", since as said, it's just an idiot light with a needle.

 

Back to normal!

 

Thanks I'm gonna invest in a real oil pressure gauge and see what's actually going on.

 

There's actually a mod that turns the dash "gauge" into a real gauge. Ford intentionally crippled the gauge into this "1/0" functionality because too many clueless owners got alarmed watching the REAL gauge pointer move so dramatically as the RPMs went up and down, and as the oil temp changed. Hopefully someone who's familiar with the mod, or at least knows where there's a thread / write-up on it, will post soon.