oil pressure gauge, what to trouble shoot first

[mexsudo]

New to me, 2002 with the 4.0
got it home and started with the basics:
I dumped the oil and filter, refilled and started it up.
pressure gauge went from zero to the middle immediately. no movement, stuck in the middle. after running for a few minutes, and checking for leaks, I shut down and restarted. same thing.
driving today, same. zero to middle.
as I said, new to me, perhaps it was like this when I bought it and didn't notice.

 

[Curious Hound]

That gauge is not driven by a pressure sensor. It is driven by a pressure switch. When pressure gets high enough to close the switch, it sends power to the gauge and the needle goes to the middle. When pressure drops below the setpoint, the switch open, needle drops to 0 and low oil pressure idiot light should come on.

You are seeing normal operation with adequate pressure.

 

[franklin2]

Ford went to a fake oil pressure gauge on most of their late model trucks. You can tell by looking at the sending unit. If it's very small with one terminal, it's the fake gauge setup. If it still has the one terminal, but looks like a larger metal can, that is the real sending unit type.

The fake unit is just a oil pressure switch that used to turn on the red light when you got below 5 psi.

Your first thing to do is get a real pressure gauge from the store and hook it up with the little plastic tubing. Run it temporarily through the back of the hood and tape it to the windshield so you can monitor the oil pressure.

 

[mexsudo]

Thanks both of you.
Had no idea that anyone used fake gauges.
Yes, I will get a real one.

 

[mexsudo]

I wonder.... Is that "gauge" a Real gauge?
could the "sending unit" (on/off switch) be replaced with a Real sending unit and make the dashboard indicator a Real Gauge?

nothing to loose, maybe I will hunt down a proper one terminal sending unit and try

 

[Curious Hound]

could the "sending unit" (on/off switch) be replaced with a Real sending unit and make the dashboard indicator a Real Gauge?

I think that works. I know it's talked about somewhere in the forum. Use the search function.

I wanted the gauge to have a numbered scale. So I replaced the switch with a sensor and put a better quality gauge in a pod on top of the dash.

 

[mexsudo]

I think that works. I know it's talked about somewhere in the forum. Use the search function.

good to know.
thanks very much

 

[mexsudo]

I found this:
https://www.therangerstation.com/tech/variable-oil-pressure-gauge-modification/#gsc.tab=0
not just a simple "replace the sender"

 

[Curious Hound]

I found this:
https://www.therangerstation.com/tech/variable-oil-pressure-gauge-modification/#gsc.tab=0
not just a simple "replace the sender"

That's the article I remembered. Level of difficulty varies with your skills and tool availability, as with any other modification or repair.

 

[mexsudo]

It is way beyond my skill set to pull the dash apart and solder.
swap a sender, no big deal.

Luckily we have several very good auto electric shops in Ensenada. I will open that page on my laptop and bring it and ask.

BTW: this place is a gold mine!

 

[franklin2]

To me it's not worth it to make a factory gauge actually read pressure, but it still just says "L", "Normal" and "H". I like aftermarket gauges with real numbers on them for the oil pressure and the engine temp.

 

[mexsudo]

I will probably just get an aftermarket set of gauges... more reliable.
thanks for all of the feedback

To me it's not worth it to make a factory gauge actually read pressure, but it still just says "L", "Normal" and "H". I like aftermarket gauges with real numbers on them for the oil pressure and the engine temp.