Technical Oil Pressure Warning

[EpicBlueEm]

Had my 500 (lounge) just over a week, let a friend have a quick go (crazy I know!) and she stalled it. An oil pressure warning light came up? It disappeared once the engine turned back on. Is this just a consequence of it stalling? Checked the oil levels but its hard to tell because its so clear!
Thank-you for any replies in advance

 

[Pathaleon]

When the engine stalls the oil pressure will fall but you are still in the running position of the car, hence you receive the error. Just restart the engine and carry on as you know by stalling it there isn't actually a fault in the system.

If you see the error without stalling id stop the engine as soon as possible and seek assistance from a recovery truck etc

 

[John202020]

In most cars if you stall it, the battery and oil light will come on as too will the hand brake light when you apply it to restart it.

 

[ahmett]

As said above, that should be fine. Check the oil level to be safe, if it looks fine and the light doesnt come on keep on driving as if this never happened.

 

[EpicBlueEm]

Thank-you everyone, everything has been fine since!
Was probably a silly question to ask, but I'm a natural blonde haha

 

[Pathaleon]

Thank-you everyone, everything has been fine since!
Was probably a silly question to ask, but I'm a natural blonde haha

The way the error presents itself is certainly worth worrying about. You did the right thing! After all we're all here to help one another

 

[czgriffin]

get it checked out... especially if it starts flashing while driving. I ignored it and wound up needing a new engine on my 2013 Fiat 500 pop at 45kmiles

 

[rallycinq]

When the engine stops turning, the oil pump stops too, hence the oil pressure warning light.

D

 

[Pugglt Auld Jock]

When the engine stops turning, the oil pump stops too, hence the oil pressure warning light.

D

Exactly as rallycinq says. The engine has oil in it's sump and the engine has an oil pump which is directly driven by the engine. The oil light is connected to a pressure switch screwed into the engines oil system. When the engine is not running the oil pump is not being driven so there's no oil pressure to act on the pressure switch which is designed so the oil light will light when there is no pressure - So, engine stationary, oil light lit.

When you start the engine the oil pump is immediately driven by the engine. (if the engine is turning so must the pump - unless something is actually broken!) It immediately sucks oil up from the sump (which is why you need to check the level from time to time - got to be enough!) and pushes it, at pressure (commonly around 40 to 60 psi) round all the bits of the engine that need oil. As it goes it pushes on the oil pressure switch which turns off the electricity to the oil light on your dash and so the light goes out. Of course if you stall the engine it stops turning so the pump stops turning so there's no oil prerssure so the light comes on! Voila!

 

[kanna]

Hi everyone, I have a 2012 Fiat 500 with a 1.4 engine and I’ve run into a problem. The car started showing a low oil pressure warning and stalls. Then it’s hard to start, but eventually it runs. Sometimes it won’t let me press the gas all the way and won’t rev above 3000 RPM. At the service, they checked the oil pressure and fuel pressure — everything is normal. They also thought the catalytic converter might be clogged, but it’s fine. Now we don’t know what to do. If anyone can help, I’d really appreciate it.

 

[A3jeroen]

Earth cable between battery and engine 100% Ok? and the earthing of the oilpressuresensor?
I can imagine that the low pressurewarning gets the car in some sort of selfpreservationmode.

gr J

 

[kanna]

Earth cable between battery and engine 100% Ok? and the earthing of the oilpressuresensor?
I can imagine that the low pressurewarning gets the car in some sort of selfpreservationmode.

gr J

We didn't check this, when it stalled, it gave an oil error and a battery error, we replaced it, but nothing changed.
Now we're going to change the crankshaft sensor because it's also acting weird, it's not giving any readings, but it's working, and we're just out of ideas...

 

[Mike1alike]

Hi everyone, I have a 2012 Fiat 500 with a 1.4 engine and I’ve run into a problem. The car started showing a low oil pressure warning and stalls. Then it’s hard to start, but eventually it runs. Sometimes it won’t let me press the gas all the way and won’t rev above 3000 RPM. At the service, they checked the oil pressure and fuel pressure — everything is normal. They also thought the catalytic converter might be clogged, but it’s fine. Now we don’t know what to do. If anyone can help, I’d really appreciate it.

You should have opened a new thread. This one is old and your problem sounds different.
Oil warning light does come on the dashboard if the engine stalls. Because engine not running makes oil pump not running sobno pressure and key remaining turned on feeds voltage to dash light so it's normal for it to turn on. It should always turn on when you put ignition to MAR. If it doesn't, it's not working, bad pressure sensor or some other electrical problems.
So oil light on is a red herring to your problem. It's very good you had it checked and the confirmed oil pressure is actually good.
Your problem is basically engine stalling. There are multiple possible causes for that.
First one, easy to check too, is the crankshaft positioning sensor. When it works it tells the ECU the engine speed, RPM. If it doesn't work, ECU is not "seeing" engine movement so won't inject fuel. So when you have the problem and engine doesn't start at first try after stalling, watch the RPM gauge. If needle goes to 200~300 RPM, sensor works. If needle stays down, below 0, bad sensor, new sensor will be the fix.

 

[Mike1alike]

Now we're going to change the crankshaft sensor because it's also acting weird, it's not giving any readings, but it's working, and we're just out of ideas...

Sounds like you're on the right track. That's what crankshaft sensors usually do and that makes it impossible to some to diagnose because when it goes bad there is no stored error about it. Usually this sensor stops working intermittently. Most of the times when it gets hot it stops sending the signal. So new sensor is good way to go, especially if you noticed it not working while cranking, if RPM gauge needle stayed down while cranking.

 

[kanna]

You should have opened a new thread. This one is old and your problem sounds different.
Oil warning light does come on the dashboard if the engine stalls. Because engine not running makes oil pump not running sobno pressure and key remaining turned on feeds voltage to dash light so it's normal for it to turn on. It should always turn on when you put ignition to MAR. If it doesn't, it's not working, bad pressure sensor or some other electrical problems.
So oil light on is a red herring to your problem. It's very good you had it checked and the confirmed oil pressure is actually good.
Your problem is basically engine stalling. There are multiple possible causes for that.
First one, easy to check too, is the crankshaft positioning sensor. When it works it tells the ECU the engine speed, RPM. If it doesn't work, ECU is not "seeing" engine movement so won't inject fuel. So when you have the problem and engine doesn't start at first try after stalling, watch the RPM gauge. If needle goes to 200~300 RPM, sensor works. If needle stays down, below 0, bad sensor, new sensor will be the fix.

Yes, we just ordered it now, because we no longer see what the problem could be, I opened a new post too, I’ll give you a link to it now

Fiat 500 stalls and won’t drive, we can’t find the issue | FIAT 500 (2007+)

Hi everyone, I have a 2012 Fiat 500 with a 1.4 engine and I’ve run into a problem. The car started showing a low oil pressure warning and stalls. Then it’s hard to start, but eventually it runs. Sometimes it won’t let me press the gas all the way and won’t rev above 3000 RPM. At the service...

www.fiatforum.com

 

[kanna]

Sounds like you're on the right track. That's what crankshaft sensors usually do and that makes it impossible to some to diagnose because when it goes bad there is no stored error about it. Usually this sensor stops working intermittently. Most of the times when it gets hot it stops sending the signal. So new sensor is good way to go, especially if you noticed it not working while cranking, if RPM gauge needle stayed down while cranking.

We checked everything using a laptop and while driving, because while driving the revs were limited and it showed that the crankshaft sensor was not working. I just don't know what the problem could be anymore