97 2.3 Oil Pressure Gauge Flickering At Higher Rpm

[3ncrypt3d]

Hey all,
Recently my ranger oil gauge has been flickering at higher rpm. It used to do it around 4500~, but now just with normal driving it’s doing it around 3200. I’m not hearing any abnormal noises, but it makes me uneasy to drive when I can see the pressure gauge going down. If anyone has any suggestions on what to try, it would be appreciated.

Edit: Figured I’d give more info. It only does it at higher rpm, 3200+. The higher the rpm, the lower it will bounce to. At idle, it stays right in the middle.

 

[Dirtman]

There is technically no gauge because there is no true sending unit. There is only a pressure switch (just on or off) when the switch is on the guage goes to the halfway mark.

If the guage is flickering the most likely issue is the pressure switch shorting out. At higher rpm there's more juice from the alternator so the switch reacts.

Start by checking the connection to the switch/sending unit, but they are cheap enough i would just replace it.

 

[3ncrypt3d]

There is technically no gauge because there is no true sending unit. There is only a pressure switch (just on or off) when the switch is on the guage goes to the halfway mark.

If the guage is flickering the most likely issue is the pressure switch shorting out. At higher rpm there's more juice from the alternator so the switch reacts.

Start by checking the connection to the switch/sending unit, but they are cheap enough i would just replace it.

Well, I bought a new sender, took out the inner fender well. The stupid cable was halfway off. I used some channel locks to kinda crush it a little bit, and stuck it back on. The issue is gone now. I was starting to agree with you, because it would bounce when I went over bumps. Thankfully, Indiana has a lot of bumps so that confirmed that theory. Thanks for the help!

 

[tomw]

I remember frost heaves on the highway from Lafayette up to Gary. Right lane was BUMPY, the left lane not so much.

That said, some years of Rangers had a problem with the pan gasket turning into granules that plugged the oil pump pickup screen, and starved the pump & engine for oil. Two solutions, remove the pan, clean and replace and use a length of wire(coathanger?) bent as needed to scrape the crud from the bottom of the pickup. You had to go in through the drain plug... Not the best, but better than nothing.
I don't remember the years, but is was mid-90s, maybe.

If you are satisfied your problem is fixed, cool, but if you wonder, temporary installation of a real, mechanical oil pressure gauge and a bit of observation of developed pressure would reassure.
tom

 

[fastpakr]

Curiously, I had the exact same experience on Saturday in my first long road test with the V8 swap. About fifty miles into the return trip, the needle started flying all over the place. Sometimes close to the top, sometimes zero, sometimes right in the middle where it normally goes based on the pressure switch. The movement was incredibly fast too. This is with a new sending unit that I installed during the project. It happened again as I pulled back into town. Like you described - no associated noises or RPM correlation to make me think it's a mechanical issue. I'll try reseating the connector on the sending unit. It's possible that it's just not tightly clipped in.