I'm curious; if the engine runs out of oil, will it shut off automatically?

I see this is an old thread, but I guess I missed it the first time.

I see there were some answers that were funny but facetious (as in, yes it will shut down, through self-destruction), but I wonder if some PriusChat ingenue may come by some day and read it, and take it seriously. So....

The engine does not contain any sensor that will tell any computer in the car when it is running low on oil. It has only an oil pressure switch, which only tells the computer when the oil level has fallen so far that the oil pump is no longer circulating it. (Other reasons for the pressure to be too low could be severe wear of the pump itself or the bearings, neither of which is ever likely to happen except as a result of the first possibility happening first.)

Engine bearings do not have little balls or rollers like wheel bearings and the like. Engine bearings are smooth metal riding directly on smooth metal, except for the very thin layer of pressurized oil being pumped in between.

That means whenever the oil pressure light comes on, you're not looking at a warning, you're looking at an emergency. The faster you turn the engine off, the more of it is still there when you get oil back in it.

I haven't seen anything in the manual to suggest it turns itself off when that happens. Even if it did, for reasons that should be clear, it makes no sense to rely on that and wait for it to happen.

My driver's training classes advised a simple habit of pulling the dipstick while the tank is filling at the gas station. It's advice that never gets old. Even though the Prius tank is small and I usually fill at 1/2 in the winter, there is still plenty of time to check the oil. (I just pull both the filler door release and the hood release while getting out of the car.)

I saw someone upthread write of checking every other fillup. Surely that's adequate too. It probably wouldn't work for me (I'd spend more time trying to remember if this fillup is even or odd than it takes to just check the silly oil). For me, the one surefire way to make sure I do something habitually is to just do it every time.

-Chap

 

Problem with that is it takes quite a long time for all the oil to eventually drain down from the top end. There's quite a bit of oil stored in the VVT section filter area and the cam actuator area.
It will read about 1/4 to 1/3 inch low on dipstick on a gas station check. Try it. Check gas station then check first thing in the am.

But its better to have the engine oil consistently overfilled a little than consistently under filled imho. I think the main issue with the G2 motor is its a tiny little engine and needs every drop of oil it can hold. Couple that with most folks get a dealer oil change with dino oil so it does not have excellent lubrication to begin with and its a perfect storm.

A very tough Little motor that has very few issues but unforgiving on very low oil.

 

Ed, that sounds plausible, that the oil takes a while to settle back down to the pan, but in practice I've never seen much difference. There has to be some, but in my experience it's not noticeable. Checking the oil right after shut down, then rechecking after sitting overnight: about the same. Maybe more of a factor with other cars though.

 

Maybe it is because I am in my 5th decade, but I find it almost impossible to read the dipstick after the car has been running.

There is always oil streaked up and down it and I am never sure where the true reading is.

This did not seem to be a problem with my 1957 Chevy, my 1962 Ford Custom. My 1972 Chevy Vega or my 1970-something Opal. But with my recent Toyotas, it is a problem. I pull the stick, look at it. Shake my head, wipe it off and reinsert stick, wait about 40 seconds and pull it out again, but still can't get a clear read.

I try to check every Saturday morning before driving any of the cars. I usually manage that about 50 percent of the time. I am with Ed, though. I trust the cold oil reading much more than any other.

 

same here, i think synthetic has also added to the problem.

 

I thought the poster here was joking, but I guess if you don't know much about cars it is a legitimate question. Reminds me of a motorcycle where it kept getting low on oil and I decided to ignore it. Coming up a mountain it let me know but piston rod #3 coming through the block making a 3"x3" hole. made it to the top of the mountain and she stalled. Funny part was I got her running again with a full choke, long enough to coast down the other side and make it to the park and ride.

 

It doesn't seem that different to me (admittedly, these days, I'm driving a Gen 3, with its different engine, and 0w oil, but I don't remember big differences with my old Gen 1 and the 1NZ engine, either. With the Gen 3, my gas station readings are pretty much right where I left it in the driveway when I changed it).

Main thing, if it's consistent from fillup to fillup, you're staying ahead of damaging surprises, which is really the point. You're probably not going to bother adding any unless you see it heading toward the low mark.

-Chap

 

Hmmm....i noticed it a few times as I topped off what looked like low during gas station and then the next morning I'm overfilled.
Maybe its the altitude I'm at which is ZERO....lol....

 

Hey bud,

I know it's an old post but I just wanted to share an event that happened to me...

A month back I checked my dipstick and it was totally dry I mean totally! and the car was driving and functioning ok... I didn't check the dipstick and let it go for a long time and when I checked It was all dry but then crazy thing is the car drove fine before and after I filled it with oil.


I guess Toyotas are bulletproof and that running out of oil wont kill them, at least in my case lol.


Just wanted to share this with you guys.

 

My 2010 ran dry (no oil on stick) after a 400 mile round trip once when junior at the Dealership changed my oil and left the filter bowl "lose". It took 3-1/3 L to bring it up to full so it had appx 1 liter left. This was at +80,000 miles and it then began burning oil @ 1/2 liter every 5,000 miles until I got rid of it at +150,000 miles. You will see higher oil usage now than before and all you can do is check/top it frequently to minimize any further damage. You did not get off scott free and these engines are NOT bullet proof....they are aluminum. Best wishes.

 

On another note..... No oil on the dipstick does not mean the engine ran out of oil. It just means the owner was a bit negligent in maintaining proper oil level. If there was no oil pressure warning light, then adequate pressure was maintained. I would imagine you were right on the ragged edge.

Here's what I don't understand. I had purchased a 1989 Mustang LX 5.0 convertible in the summer of 1990 as a birthday present for myself. It had a warning light for oil level that would illuminate if the engine oil reached 1 quart low. It was two words, in orange that said "Check Oil". It's incredible to me that this (or something similar) isn't standard equipment in all vehicles.

 

I would be cautious about even that much complacency. The engine is partially lubricated by oil pumped through the galleries. The other part, as I understand it, is oil splashed up by the spinning crankshaft, which depends on the level of oil in the sump. There is a 'low' level line on the dipstick, which is not all the way down at the end.

It is, sad to say, safest to assume that the engine that was run in this condition is, long term, not the engine it once was.

-Chap

 

a 2014 is already burning that much oil? Only 4 years old?

I better take a look at my dipstick today.

Just noticed this thread is 3 years old.

 

Wait a sec, insn't oil check about every 4th day on your maintenance rotation, already??

Excessive oil consumption. Issue resolved by Toyota. | Page 6 | PriusChat

 

That diptick is getting hard to read again. Warm or cold, its all smeared. Cant seem to get an accurate read. Maybe wait 10 minutes?

But other than that, the Starship is running like a champ. Smooth & quiet.

 

Yeah, wait a bit longer, and/or flip it over, one side is usually clearer. I suspect any oil consumption you have is from wiping off the dipstick though, every second day, lol.

 

It's spot on one minute; then a few minutes later it looks like it's way overfilled. But... at least I can see it.

Both sides of dipstick look the same. I will check again after driving, when it has a warm engine.

Just another Prius Oddity.

 

Couldn’t you just check it in the morning, after it has sat all night?

 

Didn’t the V6 in Camrays have a problem with the oil staying in the heads due to sludge? The oil level should not rise after the few minutes it takes for the oil to drain back down. And that amount should not be that much.

 

I agree, first thing in the morning while it is cold and the first pull of the dipstick will be the easiest to read.