# Turbo charger run after engine shut-off



## 5SeriesNatsFan (Mar 8, 2010)

I pulled my 335d into the garage, shut the engine off and for the first time in about four mohths of ownership the turbo charger kept running for about three minutes. Have any of you experienced this condition? What causes it? Thanks for your thoughts.


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## d geek (Nov 26, 2008)

That would be impossible for the turbo to continue to run after the engine is shut down. I bet it was an auxillary fan.


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## tlak77 (Aug 5, 2009)

d geek said:


> ...I bet it was an auxillary fan.


:thumbup:


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## 5SeriesNatsFan (Mar 8, 2010)

Thanks for the correction. What causes the auxiliary fan to continue running after engine shut-off?


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## Snipe656 (Oct 22, 2009)

Something that needs to be cooled down. My car has only done it once or twice in the year I have owned it.


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## d geek (Nov 26, 2008)

Could be that the engine coolant or AC refrigerant was warm enough at shut down that the cpu determined that the fan should be on for awhile longer.


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## Snipe656 (Oct 22, 2009)

When mine happened it was really at the oddest of times in regards to length of driving and outside temps. Had too many other cars that do the same thing so never worried about it much. Have had some cars where it would get stuck on so always have a slight worry of that when shutting off a car and hearing my fan still going.


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## Philm35 (Aug 19, 2010)

On every car I've owned for the last couple of decades, the cooling fan has occasionally run for a period after the car is shut off. Completely normal behavior.


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## Flyingman (Sep 13, 2009)

It was definitely not the turbocharger, you'd never hear it running. Besides, it needs exhaust flow to spin so with engine off it is not running.

Some diesel cars/trucks have an engine shutdown delay. When you shutdown and remove the key the engine actually keeps running for about a minute to cool down the turbo, then it auto shuts off. Weird.

There are up to two or more electric cooling fans on the radiators, for the cooling water, engine oil and transmission fluid, perhaps, depending on the car.

These have thermostats that turn then on or off, and sometimes the fans will run for a few minutes after you shutdown.

I've notice the 335d does it once in a while, and sometimes it has caught my attention since I know I had not driven far or long to justify it being on.

Perhaps it went into the recycle mode on the Particle Filter and that may make the fan run.

Definitely nothing to worry about.

I've also heard what I think is the fuel pump in the rear under part of the car after shutting down the car. Not sure why that would continue to run for a bit?:dunno:


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## Snipe656 (Oct 22, 2009)

Flyingman said:


> I've also heard what I think is the fuel pump in the rear under part of the car after shutting down the car. Not sure why that would continue to run for a bit?:dunno:


My truck you can distinctly hear a sound for a few seconds after shutting it down. I think they said it is the injectors cycling but the sound I hear seems more center of the truck so perhaps it is the pump for the injectors to be cycling. Regardless, it is something they added to it with one of the updates and is the exact same sound I hear when turning the key to on but not starting it due to waiting on the glow plugs. I never have noticed a sound like you describe on the car but might just be my bad hearing and it really is doing it.


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## 62Lincoln (Sep 26, 2004)

Could it have been the purge cycle on the DPF?


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## nok (Mar 14, 2010)

yes, it's the dpf cycle. you should be able to smell burning coatings the first few times it happens. if it doesn't complete the cycle on the road, it will happen after every short trip for some period of time.


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## stan01 (Jan 15, 2010)

Yeah, smells kinda like burnt fish.

So, my car did the burn yesterday evening.
Drove to work (20 miles) but then today on the way home the SES light came on (2700 miles).

Coincidence?


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## Snipe656 (Oct 22, 2009)

Smells like pee filled baby diapers to me, but never noticed a noise associated with it. Probably my poor hearing.


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## Stevarino (May 14, 2002)

*Cooling fan*

Did the PDC redelivery. Hard track use (a lot of full throttle bursts) of the factory supplied 335d. During breaks, the 335d radiator cooling fan would stay running for quite a long time after engine shutdown. 6-8 mins as I recall.


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## Stussy109 (May 23, 2010)

nok said:


> yes, it's the dpf cycle. you should be able to smell burning coatings the first few times it happens. if it doesn't complete the cycle on the road, it will happen after every short trip for some period of time.


that is correct.. diesel particulate filter cooking off the junk


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## DnA Diesel (Jul 31, 2010)

The water pump also cycles while the aux fan in on, to increase the effectiveness of the cool down (vice just cooling waster in the rad).


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## tlak77 (Aug 5, 2009)

DnA Diesel said:


> The water pump also cycles while the aux fan in on, to increase the effectiveness of the cool down (vice just cooling waster in the rad).


hm I though we don't have electrical water pump


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## HIREN (Jul 14, 2006)

Us 2010s don't, but the 09s do and maybe the 11's as I hear they brought back the winter REST function for 2011. 

What the OP heard was definitely the cooling fans after a DPF burn cycle. 
I thought I would smell the burnt marshmallow smell every burn cycle, but it stopped smelling after about 5000 miles. 

If you monitor the water temp through the secret OBC menu you'll notice during a burn cycle the coolant temps sky rocket past the usual 90 degrees all the way to 100 or so Celcius. So it makes sense that the fans would run to cool everything down if the car is turned off during a burn cycle.


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## Snipe656 (Oct 22, 2009)

I read in a thread on here that there is a way to do the Rest on the 2010s but forget what method they were claiming would work. The thread was based though on the 7 series and they were saying in the thread it would apply to the 3.


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