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My ‘85 22R runs like a champ but, I just developed a problem with the oil light. My idle is set around 550RPM. Prior to today, engine cool and at idle, I’d get oil pressure around 15-20psi. Warm it would get a decent bit less. Warm and idling, my oil light would come on at times or flicker. Any time it revved at all, the light would go off. Today, my RPM’s/pressure dropped and my oil light came on but, when it revved up, oil pressure built but the light didn’t go off. Let it cool down for a time, started it and the light was off until it warmed a bit and came to an idle, when the light came on and didn’t go back off. I know my pressure is good but, the oil light irritates me. Where do I start to look for the problem? Replace the oil sender?
Here’s my oil sender setup with a stock sender and line to my mechanical oil pressure gauge.
Here’s oil pressure and light at idle.
And here’s the oil pressure and and light when slightly revved.
This morning, same kind of story. I let the rig cold idle and warm up as I was putting the trash cans on the curb. Drove to work and all was fine until I got into the parking lot. RPMs came down at one point, the oil light came on and didn't go off. Parked now. We'll see what happens on the drive home. Still no indication of any problem from the mechanical gauge. Maybe I just need to replace the pressure switch?
Well, since you have verification of the oil pressure by the steam gauge, you know, that when the light goes on, the pressure is good. Tells you the OEM system is in error. Now, the trick is to figure out just what part has failed.
Looking at your set-up, I would first ensure the wire is good. No dirt, oil, etc where the connector attaches to the sensor, and that the wire itself iss good. Try wiggling the wire around when the light is on. Flex the wire a little bit. Pull the wire off the sensor, and check the pin it goes on, make sure it's good and clean.
If it's all good, my be would be the sensor. Oh, yeah, check to make sure no dirt bits have gotten into the sensor, preventing it from reading the oil pressure. After all that, try replacing the sensor. All things being equal, the sensor itself would be my guess right off.
All this is my opinion, for what it's worth.
Good luck to you!
Pat☺
Thanks for the reply. I walked across the street on my lunch and picked up an Import Direct part from O'Reilly's. I played with the wire last night and that didn't seem to change anything. Never done this before. There's, obviously, no pressure when the engine is off but, do I need to change the switch when I'm doing an oil change and have the oil drained or will it not be an issue with oil in the system? How much oil do I need to be ready for if I remove the switch and the system isn't drained of oil? Thanks.
With oil in the truck, just unscrew the switch, and plug it with you finger or thumb until you can grab the new one and screw it in. No pressure, other than the weight of the oil above it in the system. Not much. That's why there's anti-drain back valves in the oil filter. Shut off the truck, let it sit for a 1/2 hour or so, shouldn't get hardly any oil out. Not counting what might be in the tube for the steam gauge. How much can be in there, though? Just have a good rag available
DO NOT use teflon tape or other anti-leak type stuff on the switch, BTW. Always ensure the threads of the switch and the hole it goes into are nice and clean. The system gets it's ground from what it's screwed into.
No, this is great. Thanks for the input. I can always just go digging into things but, I’d rather have more info on what I’m getting into than not having any. Thanks again.
Quick update on this. Replaced the switch and all seems to be working correctly. Pulled the old switch and barely a drop of oil came out. Was an easy replacement. The dash light comes on at startup then goes out, like normal. For now, I'm assuming things fixed.
Honestly, though, I would have just pulled the bulb in the idiot light and gone with the mechanical pressure gauge. I guess the idiot light would be a decent back-up, if you don't scan the mechanical gauges very often. For my own personal use, IF it were mine, I'd just use the steam gauge. More accurate Just me, though.
I do keep a vigilant eye on the mechanical gauge. For whatever reason, I like some of these original systems to work as they should. I'm a little different like that. When I first got my pickup, I did all kinds of searching and info gathering and hooked everything back up to get my dome light and key buzzer working again.
Within a week of buying both 87's I have had, my pickup and the 4Runner I once had, I had cut the wire to the key buzzer. That thing drove me nuts. I was going to do it to the 99 my lovely wife bought, but she won't allow. She wants it as factory as possible. Drat it. It makes me crazy when I have to drive her truck. But she's the boss. Happy wife, happy life, and all that.
Sep 28, 2022 | 10:28 PM
