Low Oil Pressure

[Ordak]

I have a 1996 Ford Ranger with the 2.3L 4-cylinder and it is reading now reading low oil pressure until it warms up for like 5-10 minutes. I looked around and could not find anything with a real solution. I did change my oil recently and used the correct oil(5w30). Is there a valve that opens when it is cold out to get oil flowing that could be sticking? It is in the 30's (Fahrenheit), but it has not happened all winter(even when it was between 5-15F) until now so i am not sure if i have a real problem. I do not think it is the oil pump going bad because it would not go from low to correct pressure.

 

[adsm08]

You need to start by doing a mechanical pressure test.

Since the oil pressure sender is a variable resistor it's operation can be effected by temp and since your gauge (I am assuming this is going by the dash gauge) is doing basically the opposite of what one would expect the actual pressure to do I would guess the sender is the issue.

 

[Ordak]

yeah i would say if it was cold it would have a higher oil pressure because it would not flow correctly. So you are saying i need to get a new Oil pressure gauge sender? I am going to do a mechanical test first to double check if the dash gauge is reading wrong

 

[adsm08]

That is my gut instinct.

On a mechanical test you should see the pressure start out high and then drop off as the oil warms up. Since your gauge is doing the opposite of that, my first guess would be a bad sensor.

 

[rangergi]

I have the same problem, I have done tests and figured out that it is just my oil pressure switch getting clogged. I am going to replace the switch with a sender soon.

 

[wildbill23c]

I installed a mechanical gauge in my 84 Bronco 2, when its first started cold the oil pressure is pretty high around 40psi, after it warms up I find the gauge reading extremely low around 5-10psi. My only assumption is possibly I need a new oil pump, as I would think normal oil pressure should be quite a bit higher than 10psi driving down the road.

But yes, your problem seems to either be the gauge malfunctioning or the sensor itself is bad.

 

[logman7777]

Doesent the 94-97's have the dummy gauge and low oil pressure light? I would check the sensor and while you are there (LH side of the timing cover behind/below coil packs) remove it and do a pressure test with a known good pressure gauge.

 

[adsm08]

I installed a mechanical gauge in my 84 Bronco 2, when its first started cold the oil pressure is pretty high around 40psi, after it warms up I find the gauge reading extremely low around 5-10psi. My only assumption is possibly I need a new oil pump, as I would think normal oil pressure should be quite a bit higher than 10psi driving down the road.

40 is normal across the board when cold. By the time the engine hits temp it probably would be between 5 and 15 depending on engine wear and oil viscosity. Most spec sheets call for about 25 at 2000 RPM at temp.

 

[wildbill23c]

40 is normal across the board when cold. By the time the engine hits temp it probably would be between 5 and 15 depending on engine wear and oil viscosity. Most spec sheets call for about 25 at 2000 RPM at temp.

Hmm, guess mine is normal LOL, I run 10W-30 oil in it, and with my oil pan bent and leaking I guess I shouldn't expect to have much oil pressure anyhow LOL.

 

[adsm08]

Wel the oil pan isn't supposed to be a pressure seal. As long as the oil in the pan is above the pickup none of that should really matter.