Oil Pressure

[redv2k]

Recently took my pickup to a PeP boys for an oil change. The day after I started my engine and the gauge showed no pressure. I checked the oil level and it was ok. About a mile down the road the oil pressure popped up normal.

Not being too smart with engines I assume with the correct oil level oil would circulate in a running engine and it was just maybe a gauge or sender problem?

Any thoughts? I'm not too technical but can usually follow instructions and I have a manual.

Thanks
Red

 

[RonD]

Ford uses an oil pressure switch, it is either on or off, so oil pressure gauge is either 0 or 1/2(approx.).
Oil pressure switch is set for 6psi pressure, below 6psi switch is off and gauge is 0, above 6psi and gauge is 1/2.

Oil pressure comes from have too much oil going out to the bearings and valve train.

The oil pump pulls oil out of the oil pan and sends it to the filter, oil passes thru the filter and to the main oil passage, this is often where the oil pressure switch is, then the main passage breaks off into smaller passages to distribute oil to the bearings and valve train.
The gaps in the bearings is where most of the "back pressure" comes from, the oil pump(hopefully) pushes out more oil than can flow out of the small gaps in the bearings, so a "back pressure" is built up, that that is the Oil Pressure of an engine.

Your drop to 0, without associated valve train noise of actual low pressure, was probably from some air left in oil pump, it's passage to the filter, or filter itself.
Basically a Burp from some trapped air.

That doesn't happen often but isn't unheard of either.
But keep an eye on the gauge over the next few days, it should not do it again.

Because of Gravity lower oil pressure will cause valve train noise first, higher places in the engine have lower pressure to begin with so a drop in pressure effects that area first.

 

[redv2k]

That doesn't happen often but isn't unheard of either.
But keep an eye on the gauge over the next few days, it should not do it again.

It did it again yesterday but I've just been out there to start it and the oil pressure came straight up.

I just wanted to make sure I wasn't causing any damage to the engine. I've had this pickup for 4 years now. It's served me well and I've grown attached to it.

Thanks for your comments and for sharing your knowledge

Red

 

[RonD]

Nice looking and clean Ranger


There may be some debris in oil switch, if it continues to do it you may want to clean it out.
Find the oil switch, usually near oil filter and it will have only 1 wire connected.
Remove it
Unplug coil, both coils if 2.3l
Put a towel/rag down under oil switch hole
Crank starter motor, count to 3
Should be some oil on the towel and leaking out the hole.
Clean switch tip and put it back in
It has a tapered thread so should self seal, some like to use sealing tape which is fine but.....................
This is a 1 wire device, which means it uses the block/engine as the "other wire"(need 2 wires for a circuit), so if you use tape leave the bottom threads bare so they make good contact with block/engine.

 

[ick]

Check the oil pressure with a manual gauge to ensure the dash gauge is accurate. It shouldn't take a mile of driving for oil pressure to come up. Perhaps the pep boys filter anti-drainback valve has malfunctioned or they used the wrong oil viscosity. If the test shows the pressure comes right up but the dash gauge is incorrect, suspect the sending unit.

Sent from my SAMSUNG-SM-G920A using Tapatalk

 

[redv2k]

Thanks for the reply, appreciate your input. I've started the engine a few times now after the 1st 2 delayed pressure readings and each time the pressure comes straight up. I'll let sleeping dogs lie for now.