Help me make sense of this Oil warning light coming on please

[e9999]

If I start the engine and keep it at idle, after about 15s or so the oil warning light comes on.
When I check the engine oil level with the dipstick it shows as full.
When I check the oil pressure gauge on the dash at idle it shows the pressure to be a small bit (2 or 3 needle widths maybe) under the upper line of the normal operating range (3rd line from bottom, second from top).
If I run the engine up to 2000 rpm, the warning light stays on but the oil pressure gauge needle reacts and moves up a bit to the upper range line (3rd from bottom).
Engine runs smoothly, no weird noise.

So, I have not yet put a pressure gauge on the oil system but for now, it looks like there is oil and there is pressure.

I imagine that there is an oil level sensor.
I'm assuming that there is a wiring short someplace in the oil level sensor circuit or that it's gunked up / faulty. Is that indeed likely? Which should I start with? I'm thinking that since it takes a while for the light to come on it is probably not the wiring but that's not obvious admittedly.
Anybody had luck cleaning up the sensor or do they need to be changed? And are they still available?
TIA

 

[hisandhers80s]

The Oil Level Sensor is still available, and if I am not mistaken it goes into the side of the upper oil pan.

 

[e9999]

Thanks!
Good news, but almost $300 yikes...
Can it be cleaned or fixed somehow?

 

[Mag71k5]

Thanks!
Good news, but almost $300 yikes...
Can it be cleaned or fixed somehow?

They look simple enough, maybe make sure the solder is solid that runs across it?

Could always attempt it at your next oil change.

 

[Teddy]

Thanks!
Good news, but almost $300 yikes...
Can it be cleaned or fixed somehow?

Those sensors are very inaccurate with age. Not worth the hassle of trying to repair if it's not leaking. Especially if you check your oil regularly. They like to break when you remove them and then you will be buying a new one.

 

[e9999]

good point about it possibly breaking upon removal, that's always a bummer.
If you disconnect it, does the warning light go away or is it always on?

But to be clear, does everybody agree that it's likely just the sensor and nothing serious given what I see otherwise?

 

[alia176]

Just to be clear, is your low oil level light coming on? If so, this is the sensor in the pics. Here it is in red in one of the pic. I replaced the O ring while I had the upper oil pan out, but you should be able to remove it for troubleshooting purposes. Like you said, the float might be sticking due to gunk so a thorough cleaning is prolly all it needs.

Sounds like you're getting decent oil pressure based on the needle gauge.

 

[jonheld]

good point about it possibly breaking upon removal, that's always a bummer.
If you disconnect it, does the warning light go away or is it always on?

But to be clear, does everybody agree that it's likely just the sensor and nothing serious given what I see otherwise?

The dash cluster oil lamp is only illuminated by the oil level sensor in the sump. Disconnecting the sensor will keep the lamp off.
There is also a delay built into that circuit to prevent the lamp from blinking every time you hit a bump.
Personally, I'd try to fix it. But that's just me. Have a new gasket at the ready. 90430-27001.

 

[Marvelicious]

Yep, no big deal. I won't absolutely swear to this, but mine seems to be less sensitive on a fresh oil change than when I'm nearing time for a change. With a fresh oil change, it won't come on again until my valve guide seals have leaked at least a quart and a half. By the time I'm due for a change, it's coming on before I'm at the bottom of the dipstick hash marks. Still, it's not an "Oh s###" light, it's a "maybe check your oil" light. It annoyed me at first, and I thought about trying to clean it up, but once I got the feel for how it seems to work, it stopped being a pressing issue.

 

[e9999]

well, I'm assuming it is the oil level light coming on, I thought there was only one for oil. It looks like an old-fashioned little hand pumped oil can. Towards the middle right of the dash bottom IIRC.

A time delay circuit would explain why it takes 15s to come on.

And if disconnecting it turns the light off that should mean the wiring is good.

I had assumed that the warning light was for both low level and low pressure... That is not the case then?

But looking at that pic above (thanks!) that sensor does not seem to be that delicate, I may just remove it and clean it. I'm guessing it can be done with full oil level without flooding the garage?

 

[Dark Knight]

You can find them for half the price when Toyota parts online has sales going on. Right now South east dealers are doing 15% off for the next 6 days

 

[e9999]

Thanks, good to know but will likely try the DIY fix route first.

 

[Mag71k5]

well, I'm assuming it is the oil level light coming on, I thought there was only one for oil. It looks like an old-fashioned little hand pumped oil can. Towards the middle right of the dash bottom IIRC.

A time delay circuit would explain why it takes 15s to come on.

And if disconnecting it turns the light off that should mean the wiring is good.

I had assumed that the warning light was for both low level and low pressure... That is not the case then?

But looking at that pic above (thanks!) that sensor does not seem to be that delicate, I may just remove it and clean it. I'm guessing it can be done with full oil level without flooding the garage?

I flooded the garage because I forgot the seal during my diesel swap, but it may sit lower in the diesel pan.

The oil symbol light is strictly for oil level, it has nothing to do with pressure.

 

[e9999]

Yup, you are right, I managed to find my little owner's manual and it only mentioned level wrt to that light, nothing about pressure. Odd, I would have thought there would be some idiot light for the pressure too besides the gauge itself. Oh well.

If somebody took the sensor off with full oil on the gas engine and it did not spill, it would be good to know. Thanks.

 

[Bigtoepfer]

I think that is what mag was trying to tell you originally when he posted the first picture, that you could pull it out and clean it when you do your next oil change to prevent spilling.

Based on the location I think it's possible you will get a mess, but I'm not 100% certain.

Oddly I will get the light come on from time to time, usually when it starts to get cold in fall before winter hits right after an oil change about 1-2 minutes after starting. I'll get nervous, spend 2-3 days constantly checking the oil level, and everything will be fine, pressures are fine, etc. I've chocked it up to a quirk of the engine. Maybe some day I'll get a new sensor, but I have better things to spend $300 on.

 

[Rusty Marlin]

When mine gets a 1/4-1/2 quart low the light comes on when the engine and oil is cold, then goes out in a minute or less. I used to get nervous, but I check my oil regularly as my ACIS is working very well. My assumption is the cold oil is pooling in the head and it takes a while to get back down to the level sensor.

Does your light go back out? Or does it stay on?

 

[Bigtoepfer]

Mine goes away very quickly. Sometimes I don't even notice it because I'm too busy at the stop sign watching for other cars, but it was bright enough to catch my attention so I look down and its already gone. I think you are probably right in your assumption though.

 

[Kernal]

IME the low oil level lamp comes on when the engine oil level is ~ one quart low when a cold engine is first started often within a mile of driving but then it will go off in the next mile or so as the engine warms up. If the vehicle is driven without adding oil the lamp will come on more often and stay on longer until you reach around 1-1/2 to 2 quarts low and then it will stay on all the time even with a fully warmed up engine, IME.

How is the oil level being checked, cold engine or fully warmed up engine after ~15 minutes of driving??
Vehicle parked on a level surface, engine off?

Ditto: remove the sensor, clean with a plastic safe product, reinstall with a new gsasket, clean the harness connectors with contact cleaner, snap back together.

 

[Fj80oregon]

You can remove and oil will not spill out, oil level sits well below the bung. Clean the sensor. Be careful the float is brittle and will brake off. I have cleaned one up before same symptoms and it cleaned up and resolved the issue. Good idea to clean up the plug ends with some contact cleaner also.

 

[jonheld]

it's not an "Oh s###" light, it's a "maybe check your oil" light.

^^^^^This right here.
The sumps on these engines hold 2 gallons and are well baffled. 1 or 2 quarts low is not going to make a difference.
My oil lamp occasionally lights when I'm a quart low. I ignore it until it it's constantly on and starts to annoy me. Then I check the oil, throw in a quart and move on with my life.