Oil pressure

[Mustang351V8]

My oil pressure in my truck drops to low but if i rev it up it goes back to normal it goes up and down? Please help i dont want to ruin my motor.

 

[RonD]

'92 won't have a "real" oil pressure gauge.

On the engine is an oil pressure switch, it is "open" below 5psi, "closed" above 5psi.
The gauge is grounded via the switch, so when switch closes it should show normal pressure, if open 0 pressure.

If gauge goes up and down based on RPM then issue is most likely electrical.

If you hear valve train tapping at idle then you do have low oil pressure, if no tapping then you don't so start checking electrical connections at the switch and gauge.

 

[Mustang351V8]

My motor sounds fine actually it just worried me

 

[wizkid00104]

My 2.3 does the same thing. I added a T manifold at the pressure and installed an Autogauge mechanical oil pressure gauge. My pressure was just fine.

I suspect the problem is a ground either at the gauge cluster or grounding the switch through the engine. I am eventually planning to use a hose clamp to ground my switch directly to the battery to test this.

You can also convert your pressure gauge to a real pressure gauge. See here:
http://rogueperformance.com/oilsw.html

You can get the sending unit from Rock Auto for 85 and earlier F150 w/ 302 if memory serves me correctly. The sending units are pretty cheap.

 

[exbass94]

Oil pressure is supposed to increase as the RPMs increase. It's normal. When you say the pressure is "low" at idle, just how low is it? (what PSI?) We need actual numbers to diagnose. Are you just using the stock gauge, or do you have an aftermarket gauge?