Fan activating after short journey

**loz65** · 23-01-2016,06:19 PM

I've got a new Audi A6 Avant Ultra S-tronic, which I've had for 4 months.

I've noticed that on a couple of occasions in the last week that the fan has remained on for around 5 or so minutes after I've turned off the engine, after only short journeys (less then 15 minutes and not caning it!). Whilst I appreciate that the fan will come on sometimes after a journey, should this happen in the above situations, when the weather is not exactly tropical!

**Lukenkarl** · 23-01-2016,06:21 PM

Probably dpf regeneration, but wouldn't have thought it would do it twice in a week. I am not sure. A Vcds scan of soot level would give more information

**loz65** · 23-01-2016,06:22 PM

Sorry, meant to add that on the second occasion this has happened (first time Wednesday, second time today), there was a distinct smell of engine as well!

**St3veM** · 23-01-2016,06:26 PM

Deffo a DPF regen; you stopped the engine during the cycle so it will be hot hence the fans running post shutdown to cool the exhaust down.

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**loz65** · 23-01-2016,08:38 PM

Thanks for the feedback - I do a lot of short journeys so is the best thing a blast up the motorway every week - how long for?

**St3veM** · 23-01-2016,08:46 PM

I don't know the specifics on when the regen triggers but I would have thought a good 30 mins at 60mph + at 2k rpm+ should kick it off; feel free to correct me if I'm wrong folks.

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**Guest 2** · 23-01-2016,08:49 PM

If you're only doing short journeys you should really be in a petrol.

Fans on is an early sign things will get worse if you continue your current driving style.

**loz65** · 23-01-2016,08:59 PM

Oh dear, looks like I might have to sell then - oh well, only £3000 a month depreciation so far..... Unfortunately, Audi seem to think you only want a petrol if you're after mega BHP.

Seriously, will not taking it for a blast every week not resolve this?

**Guest 2** · 23-01-2016,09:03 PM

You'd need at least 30-40mins @ 70mph in 4th gear if you're doing 100% short journeys as the soot and carbon build up will increase rapidly.

**Dave fitch** · 23-01-2016,10:36 PM

I have exactly the same car (2.0 ultra) and the same thing happening but have driven a BMW diesel for four years doing exactly what I am doing now mileage and speed wise and only ever noticed about four regens in 40,000 miles this does a regen about every 250 miles and the fan has been running after switch off a number of times and WITHOUT THE REGEN SMELL.

I read on another forum that this is because there is a minimum amount of water used to cool the engine block so that the engine heats up faster to give improved economy.

Is that not correct then?

Are people saying that if you drive less than say 50 miles a day then an ultra is not suitable? this must discount a vast majority of the population from being able to drive an Ultra and with no petrol alternative surely makes the car uneconomical for Audi to build.