oil pressure

[94STXRanger]

So today when i started my truck the oil pressure was down on the N on normal, not the r=m zone. Then one time it jumped up to normal, and went back to the n. Is there any way for me to konw if its the sending unit or the pump or what?

 

[snake]

Loose wire, gauge or sender. The oil pressure guage on these trucks is a glorified idiot light- they go to the middle when you have oil pressure (6 PSI and higher) and zero when it drops below 6 PSI. The guage should never be between these two points when it operates correctly. You may want to put a mechanical gauge on there to make absolutely sure, but I'll bet one of the three I mentioned above is the culprit.

The screen on the pump can also clog with gasket fallout, so you may want to check pressure to be sure- cheaper than replacing the engine.

 

[94STXRanger]

How do i check for pressure? today it continued to read normal, than fall down to the N, and switch back and forth a few times, now its just on the N.

 

[kevinsranger]

mine has been doing the same thing, i think the 94 and older is an actual pressuge sender not a glorified idiot light, i was gonna ask the same thing because it has been fluctuating even sitting at a light.

 

[mhughes165]

mine has been doing the same thing, i think the 94 and older is an actual pressuge sender not a glorified idiot light, i was gonna ask the same thing because it has been fluctuating even sitting at a light.

all it does is measure resisitance, its a glorified idiot light kev, install a mech gauge there only like 20 from advance/autozone/pepboys

 

[kevinsranger]

all it does is measure resisitance, its a glorified idiot light kev, install a mech gauge there only like 20 from advance/autozone/pepboys

so it is just a messed up sender or something thats causing it to go up and down? thanks im gonna have to change that, me temp gauge dont seem accurate i need to get a new sender for it

 

[mhughes165]

so it is just a messed up sender or something thats causing it to go up and down? thanks im gonna have to change that, me temp gauge dont seem accurate i need to get a new sender for it

could be the gauge wearing out, corrision in the wire or the sender....its why i usually never trust ANY stock gauges.

 

[kevinsranger]

could be the gauge wearing out, corrision in the wire or the sender....its why i usually never trust ANY stock gauges.

its pretty old, i have an extra set of gauges and i know they both read the same so its gotta be wiring or sender, i guess some water crossings could have messed them up too

 

[mhughes165]

its pretty old, i have an extra set of gauges and i know they both read the same so its gotta be wiring or sender, i guess some water crossings could have messed them up too

thats why i like the mech oil pressure gauges, there never wrong

 

[snake]

The mechanical ones just use the hole the sender is plugged into now- most use a fitting and a hose straight to the guage.

 

[94STXRanger]

The mechanical one would have the tube running to it right? filled with fluid? Do you hook it up to where the old sender was?

 

[snake]

Yes, yes, and yes. The fluid you see in the tube is oil. When you hook this up, it should have good pressure when the engine is cold, then it is normal for it to drop as the engine warms up. Not sure what pressure they run, I'd guess about 35 or more cold. The pressure will also rise and fall with RPMs. If you see fluctuations when the engine is run at steady speed, you may be having problems. The most common is the pickup screen in the pan clogging up from old gasket material falling into the pan. Eventual certain death if not cleaned out.

 

[94STXRanger]

So while shifting and getting up to speed a fluctuation in oil pressure with a mechanical gauge would be normal? I would assume it would raise as rpm raises? What would be normal psi for a warmed engine? Like what readings should the gauge go to? I might put one in and get one of those pillar pod things, maybe with tranny temp too or something else.

 

[Hahnsb2]

So while shifting and getting up to speed a fluctuation in oil pressure with a mechanical gauge would be normal? I would assume it would raise as rpm raises? What would be normal psi for a warmed engine? Like what readings should the gauge go to? I might put one in and get one of those pillar pod things, maybe with tranny temp too or something else.

Spec should be 40-60PSI at 2000 RPMs warmed up. Yes oil pressure does raise with RPMs but only until the relief valve opens. Mine hits 60 PSI at 1700 RPMs and wont go higher unless it's still cold/rev it past 5K. There is no need for a tranny temp gauge on a 5 speed, if anything, get a water temp gauge.