My 2012 Prius V with 172,000 miles started having the oil light comes on even when the oil is full?

I would not drive it anywhere.

There are a couple possibilities;

1. Actual low oil pressure with several potential causes but all severely damaging to the engine

or

2. Something is wrong with the oil pressure switch which is relatively inexpensive to fix and would not be damaging to the engine.

 

Are you seeing the light on all the time, or a lot, like easy to catch it that way? Or just blinking on now and then?

If easy to catch, like on all the time, you could try pulling the wire connector right off the oil pressure switch, and secure it so it isn't touching any metal, and let the engine start up, and see if the warning light is still on. If it's on even when the wire isn't connected to the pressure switch, you've likely just got a wiring problem.

If you have an ohmmeter, you could use that for confirmation, just clipping it between the oil switch terminal and grounded metal. It should show continuity when the engine is stopped. You want it to show no-continuity pretty much right away after the engine starts up. If that's what you see, then you could be pretty sure the right engine oil things are happening, and a wiring issue is the thing to track down.

 

Clogged oil filter??

 

There is no mention if this started after an oil change or not. If so, this my be relevant...

V

 

For anyone without the 18 minutes to watch it, that's a video about how people sometimes replace the car's original plastic cartridge oil filter housing with a metal version, and sometimes the metal version is made to fit more than one engine family by swapping its center standpipe, which is, therefore, removable. If the standpipe comes out with the filter cartridge during an oil change without anyone noticing, and the new cartridge gets installed without the standpipe present, loss of oil pressure and engine destruction can ensue.

The recommendation in the video is to stick with the original plastic housing and it won't give any trouble as long as it isn't overtightened and oil gets changed reasonably often. I'm at 211k or so on my original plastic housing and I can confirm it's doing the job just fine.

The video might not have much to say about Tina's situation, unless what's on the car happens to be one of those metal aftermarket housings, and would be kind of a freak situation even if it is.

 

They can be bad oil burners. It only has about 4 quarts so if the oil light came on it was almost empty.

An excessive oil burner can use a quart every 1000 miles - so it would be a good idea to check every other fillup.

You may hear about oil additives and flushes. They don't work on this level of oil consumption.

Make 5 years? Maybe if you don't drive much.

 

Keep in mind that this Prius generation hasn't got any oil level warning light.

The only oil warning light in this car is a loss of oil pressure warning light, otherwise known as the engine is destroying itself now light.

The oil pressure might be lost because the oil level has dropped so low that it is below the oil pump pickup. Or something might be blocking the pump or filter. Or there is a hole in an oil gallery somewhere. Hugely worn bearings. That kind of thing.

From post #1, it seems like you eliminated low oil level from being the cause. Level a little bit low can't be the cause anyway, but only level so low it's below the pump pickup.

The only way this warning light can be on and not be an emergency is if it is false: if the oil pressure switch is signaling low pressure even when the pressure is fine, or there's a short in the wiring leading to the switch.

If the light is on and isn't false, no, you can't drive it 5 years that way.

 

I think we might have a case of oil streaking on the dipstick mistaken for full.

If the dealer added oil and the light stays off now, it was oil consumption.

 

What can help: pull and wipe the dipstick, wait 5 minutes (gives oil pulled up the dipstick guide tube time to run back down), then do the check. The side of dipstick facing front of car tends to be clearer.