Morning All,

 

I've got a strange issue, wondering if anyone has come across this before? I think it's time for a trip to the dealer, but always worth asking in here first.  

 

My 67 plate 2.0 150 Diesel engine has a slight issue. 

 

The fan is running when the engine has stopped.  I know it will do this when it's hot and the engine is hot too.  drove for less than 1 mile a couple of times yesterday and this morning and when switching the engine off the fan continues to run.

 

The stop/start also isn't working.

 

The only thing I can think also, on Thursday evening I heard a noise - thought it was another car at the time, but now I'm not so sure...  It was like a clicking noise whilst I was going downhill.  

 

I've opened the bonnet and can't see anything - but with all these modern cars, not much to see is there!

 

Any thoughts or suggestions?

 

Thanks in advance..

looks similar

https://www.briskoda.net/forums/topic/422971-cold-engines-fan-high-spin/

 

Your car is likely doing a DPF active regen.

 

During normal journeys your car has likely not either, got to a hot enough temperature/not had long enough/been interrupted when trying to burn diesel soot particles from the DPF. When this happens on x amount of occasions or when the max soot threshold in the DPF is reached the car will force an active regen; the cars engine/exhaust temperature will be temporarily increased to burn off the excess soot. Hence why the fans spin more than usual, to help with the raised engine temperature.  This is usually twinned with a burning smell similar to a stuck brake.

 

A regen carried out under normal driving conditions is referred to as ‘passive’. 

 

It’s safe and perfectly normal for modern diesels.  You can assist the DPF regens by driving at motorway speeds in a lower gear and getting the revs beyond 4K for 10 mins every now and again.  I can’t recall the exact guidance but it’s in the manual.  

 

Theres no indication in the car it’s taking place, e,g; a dash light but your revs will usually increase by 200-400 rpm, the engine can sound a little rough and stop/start will be deactivated.  

 

Short, stop/start journeys aren’t the best for DPF equipped cars. Premium diesel (BP ultimate or similar) can burn cleaner and also has added cleaning detergents which can also aid efficiency of the system, engine, injectors etc. 

 

More info here:

 

https://uk-mkivs.net/topic/31023-dpf-regeneration-information-must-read-for-all-drivers-of-dpf-equipped-cars/

 

Hope this helps. 

 

 

Edited 12 August, 20187 yr by penguin17

I think it's more likely that Penguin has it right, given you have TDI. My 2.0TDI 190 does exactly the same thing occasionally. You can test it by taking the car out for a blast. Once at full operating temperature, use raised rpm (using the manual gear switch to keep rpm over 3,000 at c70mph on the motorway works for me, but everyone has their own method). Give it at least 15 minutes at the higher revs. That should solve it. If not, then it might be worth getting the dealer to have a look. But my money is on a simple regen. 

2 hours ago, penguin17 said:

Your car is likely doing a DPF active regen.

 

During normal journeys your car has likely not either, got to a hot enough temperature/not had long enough/been interrupted when trying to burn diesel soot particles from the DPF. When this happens on x amount of occasions or when the max soot threshold in the DPF is reached the car will force an active regen; the cars engine/exhaust temperature will be temporarily increased to burn off the excess soot. Hence why the fans spin more than usual, to help with the raised engine temperature.  This is usually twinned with a burning smell similar to a stuck brake.

 

A regen carried out under normal driving conditions is referred to as ‘passive’. 

 

It’s safe and perfectly normal for modern diesels.  You can assist the DPF regens by driving at motorway speeds in a lower gear and getting the revs beyond 4K for 10 mins every now and again.  I can’t recall the exact guidance but it’s in the manual.  

 

Theres no indication in the car it’s taking place, e,g; a dash light but your revs will usually increase by 200-400 rpm, the engine can sound a little rough and stop/start will be deactivated.  

 

Short, stop/start journeys aren’t the best for DPF equipped cars. Premium diesel (BP ultimate or similar) can burn cleaner and also has added cleaning detergents which can also aid efficiency of the system, engine, injectors etc. 

 

More info here:

 

https://uk-mkivs.net/topic/31023-dpf-regeneration-information-must-read-for-all-drivers-of-dpf-equipped-cars/

 

Hope this helps. 

 

 

Thanks Penguin - that has sorted it.  

 

Noob error too! Didn't occur to me as the car only has 4500 miles.  Didn't think that would be an issue.

 

Cheers, and I can relax about it now.

 

 

Regens happen at around every 350 miles

 

My 150 TDi does active regens now and again and it has done them slightly more often in the hot weather

Here you go. A summary of how it works. I took this from the engine tech guide back in 2015 when i first had a 150TDI S3. I was new to diesels and had the same questions as the O.P. at first.

This a link to the post with the link to the full document.  EA288 tech guide

 

I found some of the detail I was looking for. It identifies 5 types of regen which are reasonably self explanatory:

• Passive regeneration.

• Heat-up phase.

• Active regeneration.

• Regeneration trip by customer

• Service regeneration

 

I was also looking for some info on what information I would get about the failure of regen cycles and impending dpf issues. There is no warning that a regen has failed. However, the first warning light comes at a load of 30 grams at which point you obviously need to do a customer regen trip. The final ‘get to a garage quickly’ comes on at 40 grams hopefully allowing the car to have a service regen before the filter is NFU. (45 grams load)

 

The other interesting things that I found were:

1. “Mileage regeneration” is used as an additional safety system to keep the load condition of the diesel particulate filter low.
2. The ECM automatically initiates an active regeneration if there has been no regeneration, or no successful regeneration, in the last 465 miles, regardless of the load condition of the diesel particulate filter.
3.  “The charge pressure is adapted so that during regeneration torque does not change noticeably for the driver.”