Returning from a short journey of 10 miles  the fan was running after the engine was switched off, is this anything to do with the DPF and should the engine be left on while the fan is running, is it part of regeneration?  As usual there is stuff all info in the manual.  Does regeneration take place if the vehicle is stationary.?  Is there more info on this subject that is not covered in the manual, which only mentions driving at 70 Km for 15 minutes.  Worst car manual I have ever read.

 

Karoq 2.0 diesel 4x4 SEL

I think that it's only cooling, because the regeneration releases an important amount of heat.

There is no need for the car to be left ticking over, for an effective regen the car needs to be driven anyway so don't waste fuel leaving it ticking over.

 

The car will manage its own regens so just drive it and don't worry about it. The only time you need to take action is if you get any warning lights

The fan running on switching off indicates an active regeneration is taking place that will be interrupted when the engine is turned off.  Regeneration is started and aided by extra diesel being pumped into the engine. Stopping the regeneration will result in diesel running down the bores and diluting the engine oil. Over a period of time the dilution will raise the oil level with potential for engine damage. 

You must not be complacent about this.

Check out the Daily Telegraph motoring correspondent. The first letter here is typical of his advice:

 

https://www.honestjohn.co.uk/news/honest-johns-motoring-agony-column/2018-12/honest-johns-motoring-agony-column-15-12-2018/

 

tom

 

Be as complacent as you want IMO if the car is rented / leased and going back in 2 or 3 years. Owned by VW Finance or some other Financial Establishment.

 

This is how the Governments wanted Diesels from 2010 and how VW have these TDI's now. 

If you own a car and it is a keeper then maybe being bothered is 'Simply Clever',  look after your property and try to ensure it's longevity.

According to Skoda engineering the engine does not have to be kept running if the fan is running at the end of a journey. 

Good job, because I don't usually realise the fan is running until I've switched off the engine and got out of the car!

1 hour ago, Sanqhar said:

The fan running on switching off indicates an active regeneration is taking place that will be interrupted when the engine is turned off.  Regeneration is started and aided by extra diesel being pumped into the engine. Stopping the regeneration will result in diesel running down the bores and diluting the engine oil. Over a period of time the dilution will raise the oil level with potential for engine damage. 

You must not be complacent about this.

 

It shouldn't be a problem in normal use assuming the car is in good condition.

 

I've interrupted a few regens but have no apparent engine damage on a car with 158k miles.

 

Obviously, if the car has some other issue so that it's always mid regen when it's turned off you'll probably have problems. The same applies to people that have bought (or been mis-sold) diesels for short trips when the engine doesn't get up to temperature or chance to perform a full regen.

Just ignore it and let the car do its thing.

I recently bought a bluetooth dongle for the diagnostic port (£12) and paid £3.30 for the VAG DPF app, it's quite interesting to see the DPF do it's thing when it regens.

The old "drive it like you stole it"/"Spanish tune-up" approach isn't the most effective from what I've found as you tend to run out of road quicker, have to slow down then lose temperature which slows down the regen (DPG gases reach 600c+!!!)

Even if you can only manage 40mph, keeping the revs at around 2000rpm seems to be ample to get the regen moving along, it's load on the engine that's required, not loads of revs and road speed.

I noticed my revs were hanging at 1K on the way home from work tonight so I plugged in the dongle, fired up the app and watched what was going on.  Just by using the method above, by the time I'd driven 4 or so miles, the soot mass had dropped from 100%  to 33% and the regen process ended (it rarely seems to keep going until the level is 0% although that may be due to my journeys generally being around 18 miles with some traffic).

Seems to want to regen around every 300 miles but again, that will vary depending on journey length, frequency etc.

I use OBD11 and in engine module is number of live readings on DPF. There is detail report on DPF regen status showing if regen condition is met (goes from 0% to 100%) and if regen is active at the moment as well as regen type (active/passive). There is also some stats on time / distance from previous regen etc.

 

Yet I could not find info on other readings and they are in undefined units so could not guess their meaning.

 

If anyone has more info please share here.

On 20/12/2018 at 11:50, Sanqhar said:

The fan running on switching off indicates an active regeneration is taking place that will be interrupted when the engine is turned off.  Regeneration is started and aided by extra diesel being pumped into the engine. Stopping the regeneration will result in diesel running down the bores and diluting the engine oil. Over a period of time the dilution will raise the oil level with potential for engine damage. 

You must not be complacent about this.

Check out the Daily Telegraph motoring correspondent. The first letter here is typical of his advice:

 

https://www.honestjohn.co.uk/news/honest-johns-motoring-agony-column/2018-12/honest-johns-motoring-agony-column-15-12-2018/

 

tom

 

That’s a bit alarmist yes you can get bore wash from fuel but the system doesn’t use fuel all the time it will do a passive re gen when exhaust temps are reached naturally this can be at m/way cruise speeds and sitting in traffic the vehicle may even turn on consumers in the background to make engine work harder 

but back to OP post the fan is normal 

I can only talk from my own experience. I have run VW diesels for the last 20 years, the last nine in a car with a dpf. I generally keep cars a long time, usually 10 years or more. 

 

Passive regenerations depend on the dpf being close enough to the cylinder head to get hot enough, otherwise you are into regular active regenerations.  I don’t know whether the Karoq passively regenerates more than actively. 

 

I don’t intend to be alarmist and I maybe giving a worst case scenario.  It’s the difference between the fan only occasionally running when the car is switched off to it happening regularly.  Only the OP knows his driving pattern.  Better to be aware of the potential of a problem. 

 

I do know a lot of people are having dpf problems and not just with VAG cars (just check out Discovery and Evoque forums). 

I live in a rural area and rarely drive in big cities nevertheless I definitely won’t be buying another diesel of any make. 

 

I can only quote Honest John:

 

“But too much goes wrong with the emissions equipment on modern diesels to make them a viable proposition for someone doing less than 20,000 miles a year, unless all the driving they do is on trips of 50 miles or more. Many diesels saddled with emissions equipment are totally unsuitable for repeated short runs from cold because the DPF has to actively regenerate a lot more and if the engine is repeatedly switched off mid-active regen, the sump fills up with diesel.”

 

Tom

^^^ There are no EU Type Approved Diesels from 2010 on that are not 'saddled with emissions equipment'.

 

VW Group did some cheating on that though to 2015, and maybe after, but were caught. 

 

So now the TDI's are coming with SCR and other emissions equipment.

Knowing about any unsuitability of them for repeated short runs from cold is not much use as a piece of information once in possession of a TDI. 

 

As to the sump filling with diesel thing, maybe, could do, might do, not that common really anymore, but then it happen and oddly some Dealership staff deny having ever heard of that.

Vorsprung Durch Technik.   Buy cars or vehicles suitable for the use you want them for.

On 21/12/2018 at 20:08, Russ77 said:

I recently bought a bluetooth dongle for the diagnostic port (£12) and paid £3.30 for the VAG DPF app, it's quite interesting to see the DPF do it's thing when it regens.

The old "drive it like you stole it"/"Spanish tune-up" approach isn't the most effective from what I've found as you tend to run out of road quicker, have to slow down then lose temperature which slows down the regen (DPG gases reach 600c+!!!)

Even if you can only manage 40mph, keeping the revs at around 2000rpm seems to be ample to get the regen moving along, it's load on the engine that's required, not loads of revs and road speed.

I noticed my revs were hanging at 1K on the way home from work tonight so I plugged in the dongle, fired up the app and watched what was going on.  Just by using the method above, by the time I'd driven 4 or so miles, the soot mass had dropped from 100%  to 33% and the regen process ended (it rarely seems to keep going until the level is 0% although that may be due to my journeys generally being around 18 miles with some traffic).

Seems to want to regen around every 300 miles but again, that will vary depending on journey length, frequency etc.

Can you tell us where you got the dongle to do this please?

They're everywhere, type "OBD2 Bluetooth Adaptor" into your web browser / Google...

 

Euro Car Parts, eBay, Amazon, they all sell them.

 

I have the ELM327 one which has worked well in my Skoda's over the years...

 

 

 

On 23/12/2018 at 14:37, Sanqhar said:

I can only talk from my own experience. I have run VW diesels for the last 20 years, the last nine in a car with a dpf. I generally keep cars a long time, usually 10 years or more. 

 

Passive regenerations depend on the dpf being close enough to the cylinder head to get hot enough, otherwise you are into regular active regenerations.  I don’t know whether the Karoq passively regenerates more than actively. 

 

I don’t intend to be alarmist and I maybe giving a worst case scenario.  It’s the difference between the fan only occasionally running when the car is switched off to it happening regularly.  Only the OP knows his driving pattern.  Better to be aware of the potential of a problem. 

 

I do know a lot of people are having dpf problems and not just with VAG cars (just check out Discovery and Evoque forums). 

I live in a rural area and rarely drive in big cities nevertheless I definitely won’t be buying another diesel of any make. 

 

I can only quote Honest John:

 

“But too much goes wrong with the emissions equipment on modern diesels to make them a viable proposition for someone doing less than 20,000 miles a year, unless all the driving they do is on trips of 50 miles or more. Many diesels saddled with emissions equipment are totally unsuitable for repeated short runs from cold because the DPF has to actively regenerate a lot more and if the engine is repeatedly switched off mid-active regen, the sump fills up with diesel.”

 

Tom

 

While this is mostly true, it is refering to unmanaged regen cycles.

 

Unmanaged means that you don't know the state of the DPF and that you relay solely on cars 'vrain' to perform regen. Meaning that car performs active regen if the passive is not performed timely. E.g. if DPF deposit is higher then certain level and the passive regen conditions are not achieved, the car will start active regen.

 

So if you can see the DPF level and perform driving which fullfils passive regen conditions - passive regen will be performed and DPF properly cleaned.

 

Thus Im using OBD11and I'm regularly check DPF status and when passive regen is needed - I just drive 10 minutes on highway and I allow passive regen to be performed. And yes I'm watching when regen is complete also via OBD11 (you can watch live data and see when it is completed, but it takes around 10 minutes and if you wanna be sure without OBD11 live monitoring you may drive 15 minutes or so).

 

I noticed that after such regen I get to 0% regen state, which I believe means my DPF gets completely cleaned.

 

In conclusion, if you use monitoring you can exact know when to perform passive regen driving cycle and you can keep your DPF in perfect condition. Not warring if active regen is interrupted etc. 

 

And Im driving very short distances over the working days (3 miles commute home-work plus some short trips around city with lot traffic jam idling etc). No problems so far, and as I explained DPF cleans to 0% if you perform driving cycle exactly when needed.

 

P S. Driving 10 miles a day, I get regen cycle on around 150 miles avg, so it is one 10 minute wighway excursion every two weeks or so (depends also on outside temperature etc but that is avarage).

On 24/12/2018 at 10:23, Stefanos said:

Can you tell us where you got the dongle to do this please?

This one

https://www.amazon.co.uk/gp/product/B01AC7I7BO/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

**AdBlue heads up** 

Whilst on the subject of regens, Aldi have 6ltr bottles of AdBlue on offer, with a pouring spout for £4.99. According to the info, it has a guarantee/warranty for a year, so is worth getting even if you don’t need it straight away. 

At that price, other places are taking the p***, (pun intended).