Engine off but fan still running?

[N77A]

When i turned my engine off and take the key out my car looks and sounds like its off until i get out and hear what sounds like a fan running under bonnet?

I have got a error code about the coolant level in my car sometimes but i ignored this as i assumed it must be because its cold and i have only had the car serviced 2 months ago

 

[LR231998]

It’s what the engine does to cool after you shut it off. Think it’s to do with the turbo.

 

[SRGTD]

When i turned my engine off and take the key out my car looks and sounds like its off until i get out and hear what sounds like a fan running under bonnet?

I have got a error code about the coolant level in my car sometimes but i ignored this as i assumed it must be because its cold and i have only had the car serviced 2 months ago

Modern cars do make quite a few noises from the engine compartment after the engine’s turned off. I get a humming noise from the engine compartment in my car - I believe it’s an auxiliary electric pump to cool down the turbo.

I seem to remember your car’s a diesel? If your driving includes a relatively high proportion of short journeys, then it could’ve been mid way through an active DPF regeneration when you turned your engine off - if so, the coolant fan would be running. The coolant fan running, along with raised rpm when the engine’s idling are signs of a DPF being performed by your car.

As for the low coolant error code; is the fluid level between the min and max marks on the coolant expansion tank, or has it dropped below the minimum level? If it’s dropped below the minimum level, it could be a sign of a coolant leak.

 

[Tonezz]

I just got my Cupra on Friday and straight away noticed the same noise that stayed on when I parked up and when I took the key out.

I googled about and everyone says its normal in MK3's, like above its an auxiliary pump.

Kind of annoying if you want to sit in your car without noise after you've driven it though!

 

[N77A]

Modern cars do make quite a few noises from the engine compartment after the engine’s turned off. I get a humming noise from the engine compartment in my car - I believe it’s an auxiliary electric pump to cool down the turbo.

I seem to remember your car’s a diesel? If your driving includes a relatively high proportion of short journeys, then it could’ve been mid way through an active DPF regeneration when you turned your engine off - if so, the coolant fan would be running. The coolant fan running, along with raised rpm when the engine’s idling are signs of a DPF being performed by your car.

As for the low coolant error code; is the fluid level between the min and max marks on the coolant expansion tank, or has it dropped below the minimum level? If it’s dropped below the minimum level, it could be a sign of a coolant leak.

It just says check coolant level but is really random like i’ll go a week without the error then it will come back?
I will check the coolant level tomorrow though when the engine isn’t hot

 

[N77A]

So is the noise completely normal and turns off itself? Because i’ve been restarting and turning off the engine to stop the noise?

 

[280jl]

It would only be considered normal if it turns off by itself within 5-10 minutes.

Of it stays on forever untill the battery dies then you have a problem.

If your coolant is low, first thing to do before worrying, is top it up, ideally woth anti-freeze if not with water, if it gets low again within a few days/weeks/even a month, you have a slow leak

 

[Mr Pig]

So is the noise completely normal and turns off itself?

Yes. You do not want to stop the car doing it as it is cooling down something that needs cooling down! Just forget about it.

 

[BigJase88]

So is the noise completely normal and turns off itself? Because i’ve been restarting and turning off the engine to stop the noise?

Yes this is normal on every single car. Something is hot so needs to cool down.

usually you will hear the fan going more in the summer due to extra heat.

 

[N77A]

Just checked my coolant level with the engine cold (not driven for over 12 hours) and it is above the min line? So why do i keep getting the coolant warning every now and then? Should i still top the coolant off to the max line

 

[Mr Pig]

So why do i keep getting the coolant warning every now and then?

You shouldn't. Sounds like a fault to me.

 

[SRGTD]

Could be a faulty coolant level sensor that’s causing the ‘check coolant level’ warning to be displayed.

 

[N77A]

I left this fan running for about 5 minutes and it turned itself off. But how many times is considered normal for this to happen in a day? Happened twice so far today and once last week even though i’ve been making the same short journeys

 

[SRGTD]

I left this fan running for about 5 minutes and it turned itself off. But how many times is considered normal for this to happen in a day? Happened twice so far today and once last week even though i’ve been making the same short journeys

Your car’s a diesel? If so, IMO, not the ideal engine choice if your normal motoring is mainly short journeys.

A diesel car that’s being used for lots of short journeys will carry out lots of DPF regenerations to burn off the soot deposits that have built up in the particulate filter, and the engine fan will run when a DPF regen is happening.

If the reason for your engine fan running is a DPF regen, then you should also notice the engine is idling faster than it would do normally (i.e. when it’s not performing a DPF regen).

In your position, I’d take the car on a few decent length journeys, which should help reduce soot build up in the DPF, and reduce the frequency of forced / active DPF regenerations.

 

[martin j.]

If the coolant is really low is it possible that if you’re parked off the level the coolant may be away from the sensor causing the error? I would have the coolant at about 3/4 between min and max.

 

[N77A]

Your car’s a diesel? If so, IMO, not the ideal engine choice if your normal motoring is mainly short journeys.

A diesel car that’s being used for lots of short journeys will carry out lots of DPF regenerations to burn off the soot deposits that have built up in the particulate filter, and the engine fan will run when a DPF regen is happening.

If the reason for your engine fan running is a DPF regen, then you should also notice the engine is idling faster than it would do normally (i.e. when it’s not performing a DPF regen).

In your position, I’d take the car on a few decent length journeys, which should help reduce soot build up in the DPF, and reduce the frequency of forced / active DPF regenerations.

So today i got a diesel particulate filter light on my dash so looks like you’re right.

Will a long journey fix this or am i better off taking my car to have the dpf cleaned? ( Seen halfords offer this)

Also seen some dpf cleaners that you can add to your fuel tank, will this help?

 

[motty225]

Just take it out for a good thrash

 

[SRGTD]

So today i got a diesel particulate filter light on my dash so looks like you’re right.

Will a long journey fix this or am i better off taking my car to have the dpf cleaned? ( Seen halfords offer this)

Also seen some dpf cleaners that you can add to your fuel tank, will this help?

Just take it out for a good thrash

Yes, it needs a longer run on a clear A road or on a dual carriageway / motorway, keeping the engine revs up, which will hopefully clear the DPF and extinguish the warning light. The engine revs need to be kept at 2000-2500 rpm (or possibly higher?) for probably 20-25 minutes driving, so it’s likely it’ll need to be driven in a lower gear to keep the engine revs up. if that doesn’t work, then it looks as if you’ll need to get the DPF cleaned.

Once you’ve got it sorted, ensure you regularly take your car on some longer journeys to help minimise the risk of a blocked DPF in future.

 

[N77A]

Yeah i normally do long journeys to uni but have been on holiday for the past month. Saying that, i drove to coventry and back 2 weeks ago which is 96 miles there and another 96 back the same day so the car hasn’t been lacking in longer journeys that much?