Fan comes on every time I stop the car

[mk3Octy]

Hi,

 

My fan comes on very loudly every time I stop the car and turn it off.

 

It is a 2017 Octavia 1.6 TDI with 89k miles.

 

Is this normal?

[ords]

Yes, it's doing a regen. 

 

 

[Gammyleg]

3 hours ago, mk3Octy said:

Is this normal?

 

Yes it's a normal function but I would say NO to it doing it every time you switch off. 

 

After 3 and a half years of ownership I can count on the fingers of one hand how often mine has done a regen after a switch off.

95% of my journeys are 50+ miles though which does allow for regens on-the-move. 

 

I suspect that there may be a problem with your DPF, eg it's clogged up.

[J.R.]

The problem is more likely the journey profile, next time it happens restart the vehicle and go for a drive to allow it to complete the regen, keep an eye on the idle speed, you should see it drop back to 800rpm from 1000rpm when the regen has completed if you cannot hear the fan noise while driving or recognise the change in engine note.

[MarkyG82]

As above it's an interrupted regen. The fan is it cooling down. Some people think it's the regen continuing but that's not correct. It must complete the regen to function correctly.

[NZ100]

Mine used to do what described above and I agree with what others have said.

I started using a bottle of DPF RESTORE every now and then, it did help. 

[mk3Octy]

Hi all,

 

Thank you very much for the replies. I'll be sure to carry out the above and will also add some DPF additive to the diesel.

 

Thanks again.

[Gerrycan]

I would just like to register my personal disdain for most after market 'snake oil' additives.

In regard to DPF regen enhancers there is a common thread that while they may actually do what they claim there could be secondary damage to the dpf, or other parts of the engine especially with overuse.

 

Be aware that the additive which performs for the 15 minute (?) post injection regen will then be run through the engine for the whole tank and this may not be really good for long term holistic engine care.

 

Simply follow the others recommendation to drive on to allow the process to naturally complete. It may take longer on a cold day for the dpf to reach operating regen temperature and higher speeds on a cold day can actually work against achieving dpf working temperature quickly. Your manual will probably have some suitable recommendations although I understand that not reading the manual can be a 'male pride' thing for some  

 

If you do a lot of short journeys and few longer ones then it may be useful to get a cheap Bluetooth OBCD dongle and an app on your mobile phone to monitor DPF status so you can better plan for, and meet, regen requirements.

 

 

Edited 15 March by Gerrycan