Diesel At what stage to the dpf fans come on?

[David B]

Can anybody shed some light on where in the dpf burn cycle the fans are activated? Do they go on after the burn is complete, or are they on for the whole process? Generally if they go off and I’m nearly at my destination, I will drive a little longer till the whole thing is finished. It’s not always possible, and would like to know if I’m wasting my time doing this as the actual burn maybe over?

 

[Shopkeep]

Can anybody shed some light on where in the dpf burn cycle the fans are activated? Do they go on after the burn is complete, or are they on for the whole process? Generally if they go off and I’m nearly at my destination, I will drive a little longer till the whole thing is finished. It’s not always possible, and would like to know if I’m wasting my time doing this as the actual burn maybe over?

You can monitor the progress in the temperature screen, you will see the oil temp rise close to 100 Celsius as the engine moves into high temp mode to facilitate the burn. I find the fans stay on for the entire burn, nice to finish if possible but you won’t break it if you interrupt by shutting down the engine (you will just get the stink eye from those around you while the fans keep running in hovercraft mode).

 

[Eric]

Can anybody shed some light on where in the dpf burn cycle the fans are activated? Do they go on after the burn is complete, or are they on for the whole process? Generally if they go off and I’m nearly at my destination, I will drive a little longer till the whole thing is finished. It’s not always possible, and would like to know if I’m wasting my time doing this as the actual burn maybe over?

I do this anyway, if I am approaching home and the burn fans are going, I drive a few miles down the road till finished. Purely to stop the loud fan roar outside the house. Also if the fans continue when parked up I know I'll come back to the vehicle with a lower battery than I would like

 

[DenisM]

I had just parked the wife's Subaru in the local supermarket car park a few days ago and noticed a new Ford Ranger a couple of spaces away. The chap had locked it and was preparing to head to the shops. The familiar "hovercraft" fan lift off sound was emanating from the Ranger. I smiled and asked if it was the dpf burning off... he nodded and shrugged his shoulders.
I didn't feel smug, just philosophical!!

 

[ECrider]

Mine runs the regen a fair bit. Oil temp shows from around 101-106ish. I presume if been static no need to let idle for 5mins after fans stop whirling to protect turbos like you would having just exited a hot high speed run at the petrol station or indeed just got home as the dpf/fans stopped?

 

[landmannnn]

It appears that the fans come on when the regeneration starts and turn off when temperatures have dropped after regeneration.
There doesn't appear to be a way of telling if the regen has finished.

 

[Skydance]

Funny you should mention that, mines not done a burn for months now. Possible reason is my battery SOC is always between 60-65% at the moment. I’m doing a lot of short journeys.

I am tempted to put some Liquid Molly diesel injection and DPF cleaner in. Anyone know if this recommended?

 

[landmannnn]

Funny you should mention that, mines not done a burn for months now. Possible reason is my battery SOC is always between 60-65% at the moment. I’m doing a lot of short journeys.

I am tempted to put some Liquid Molly diesel injection and DPF cleaner in. Anyone know if this recommended?

If you doing shorter journeys the DPF will regenerate passively as you are on and off the throttle.

This means you are far less likely to get a full blown active regeneration.

If your journeys are really short it would be prudent to do a motorway or dual carriageway run for 20 minutes every few weeks.

I'm never sure about magic additives to fuel systems.