Electric Motors Running After Engine Shut Down.

[MantaRay]

On a number of vehicles I've driven I hear an electric motor/pump running for a few minutes after switching off the ignition and stopping the engine. I always thought it was an oil pump supplying oil to the hot turbo bearings until it cooled down a little, but have recently heard that this is a fuel pump running to keep the fuel system primed. Well, which is correct?

[gingejbee]

Are you sure it's not the engine cooling-fan....on some cars I've owned it runs for a while after switching off the ignition- but on others, it didn't.

[bhg481]

Neither - it's the engine cooling fan. Open the bonnet and watch it.

[EDDIE51]

^ That was my thought , If the engine is hot the cooling fan keeps running for a few minutes after the ignition is switched off.

[MantaRay]

Sorry, should have said, I'm not referring to cooling fan noise. I am aware that they continue to run after engine shut down.

[bhg481]

There are certainly no other electric motors running on my car after I switch-off the ignition.

[MantaRay]

The engine cooling fan makes quite a din and can not be mistaken for anything else. The electric motor sound I refer to is much quieter.

[MantaRay]

Typically heard on turbo-diesels after shut down.

[bhg481]

Mine's a turbo-diesel (Volvo V70), but it is 10 years old. Perhaps more modern ones are different.

[douglas9401]

Maybe you have intermittent tinnitus.

[gingejbee]

Perhaps you could ask the service department of the marques of car that have displayed this noise what it is?

[mikey4444]

Engine cooling fan it is !

[4candles]

I get the same on my Fiesta EcoBoost 1 litre petrol, albeit seconds not minutes. Will try to remember to open the bonnet before turning off next time.

[richtee]

Hi Mata,
Its probably a water circulating pump- they continue to circulate rad water to prevent localised overheating- have a look beneath your rad for any extra pipes with a small pump connected. They are fitted to some VW motors I know- Transporter among others.