Loud fan noise from bonnet after switching off

[VW Cali]

Twice following has happened after early morning drive.

I have windscreen defroster on. I drive 10 to 40 minutes and park. I turn off ignition, lock car and walk away. I hear a loud fan whirring away inside the bonnet.

What is it?

If I leave it while I do my gym or groceries etc and come back after an hour it has stopped.

Kind of surprising. I am sure I have not triggered any auxiliary heating (don't even know how to get it going).

The only other cars I have had a milder version of this are veyley high performance cars with power in the 500-600bhp range. And there it is very mild.

Here it sounds almost like a diesel generator whirring away...

 

[Loz]

DPF Regeration

 

[VW Cali]

DPF Regeration

Aha.

Wow, never heard it so loud before. We have a 63 Reg X5 diesel at home too and it's silent as a mouse.

Wonder if it's the new T6 engines, or has it always been a VW van feature?

 

[Loz]

I suspect designers will try to make the fan as quiet as possible on a luxury car and wouldn't spend the money on a fan on what is technically a commercial vehicle??

 

[VW Cali]

I suspect designers will try to make the fan as quiet as possible on a luxury car and wouldn't spend the money on a fan on what is technically a commercial vehicle??

Possibly.

I have never had a van before....anyway, seems lke slower than usual driving on coolish mornings will trigger this DPF.

I noticed there is also the AdBlue tank which the X5 doesn't have.

 

[WelshGas]

Possibly.

I have never had a van before....anyway, seems lke slower than usual driving on coolish mornings will trigger this DPF.

I noticed there is also the AdBlue tank which the X5 doesn't have.

EU6 engine hence AdBlue.

 

[WelshGas]

Twice following has happened after early morning drive.

I have windscreen defroster on. I drive 10 to 40 minutes and park. I turn off ignition, lock car and walk away. I hear a loud fan whirring away inside the bonnet.

What is it?

If I leave it while I do my gym or groceries etc and come back after an hour it has stopped.

Kind of surprising. I am sure I have not triggered any auxiliary heating (don't even know how to get it going).

The only other cars I have had a milder version of this are veyley high performance cars with power in the 500-600bhp range. And there it is very mild.

Here it sounds almost like a diesel generator whirring away...

Other have complained of this noise on the T6.
You said a short drive. If the outside temperature is 5c or less then the Auxiliary diesel coolant heater kicks in and runs to aid engine warmup until the coolant gets to 70c+. this is completely automatic and is aimed at decreasing emissions from a cold engine and aid the internal heating as Diesel engines do not produce as much heat as petrol engines. This heater will continue running for a short period after ignition off if still running at that point in time.

 

[larrylamb]

I doubt it's DPF regeneration, it's only a month old.

 

[VW Cali]

Other have complained of this noise on the T6.
You said a short drive. If the outside temperature is 5c or less then the Auxiliary diesel coolant heater kicks in and runs to aid engine warmup until the coolant gets to 70c+. this is completely automatic and is aimed at decreasing emissions from a cold engine and aid the internal heating as Diesel engines do not produce as much heat as petrol engines. This heater will continue running for a short period after ignition off if still running at that point in time.

Thanks, and it does sound like it.

Rather loud! Funny thing is I had been driving for about an hour, with about a 20 minute stop in between for groceries.

 

[larrylamb]

Have you got the 3 zone a/c climatronic fitted?

 

[Stuart]

It's not just after switching off - you'll notice it sometimes happens when driving as the idle revs are at about 1100rpm.

(Definitely not 3 zone a/c related as I don't have that).

 

[larrylamb]

Thanks, and it does sound like it.

Rather loud! Funny thing is I had been driving for about an hour, with about a 20 minute stop in between for groceries.

I can't see it being the coolant heater when you have been driving for that long. Where you in traffic or cruising along, could be just the cooling fan if the engine is quite hot.

 

[Kmann]

I doubt it's DPF regeneration, it's only a month old.

It is what I also was told. Mine did it from day 1, and on a regular basis. Especially when I have periods of many short drives, driving slowly or after driving the stop and go cues.

It smells hot and burned, and the fan goes wild for a shorter period. I made a post on the topic earlier.

PS: There are quite som post in different forums when you google this …

 

[larrylamb]

Found this googling vw dpf regeneration,

"The latest VW EU6 2.0L diesel engine (EA288) will never passive regen in normal conditions in the UK - it doesn't get anything like hot enough.

It's set up to do a forced regen when the soot load is at a certain level, or every 465 miles if it hasn't done one before. In practice ours is doing it about every 200 miles. You'd never know unless you happen to stop while it's in progress.

This makes the "take it for a decent run" advice redundant."

This could explain why it is doing it so regularly on the new adblue engines.

 

[VW Cali]

I can't see it being the coolant heater when you have been driving for that long. Where you in traffic or cruising along, could be just the cooling fan if the engine is quite hot.

Another possibility.

 

[briwy]

Could just be the radiator fans running if you have been in slow traffic and the engine is really hot. 40 mins possibly but wouldn't have thought it would need cooling after only ten minutes driving. Have a look at the oil temperature which is a better indication of engine temperature.

 

[Alibee]

It's the DPF regeneration.

Lots of threads all over the place about it, corroborated by a friend's brand new Ocean doing it regularly over here (we can only do short trips, or you end up in the sea!). Far from ideal but that's what you get with EU6.

 

[Swissian]

Seems to be common, a few threads on this, mine does it too sometimes...

https://vwcaliforniaclub.com/threads/t6-150ps-cooling-fan-running-on-after-a-drive-does-yours.14254/

https://vwcaliforniaclub.com/threads/fan-running-madly.14563/

https://vwcaliforniaclub.com/threads/engine-fan-spinning-a-lot-on-stops.14661/

 

[Stoneybroke]

Our new T6 Beach has done this two or three times already.
Another thing to watch is the fact that on the DSG the manual warns of increased idle speed. From yesterday's experience it means that the idle is about 1000rpm which means a different and louder noise when queuing and the DSG wants to pull the Cali more when holding or manoeuvring/reversing, so more brake control required in tight spaces! A little unnerving first time... Stop-start is also deactivated.

 

[WelshGas]

Our new T6 Beach has done this two or three times already.
Another thing to watch is the fact that on the DSG the manual warns of increased idle speed. From yesterday's experience it means that the idle is about 1000rpm which means a different and louder noise when queuing and the DSG wants to pull the Cali more when holding or manoeuvring/reversing, so more brake control required in tight spaces! A little unnerving first time... Stop-start is also deactivated.

That's certainly different to the Euro 5 engine.