Active regeneration happening very frequently

[DickyG]

I have a 2015 Octavia estate 1.6 diesel and the active regeneration process (burning smell, fuel range drops, engine idles fast and fan runs after engine stopped) seems to be happening very frequently given the journeys I do.

 

I use the car for work extensively and would say that roughly 80% of my journeys are between 1 and 3 hours long and probably 85% or more of the miles I do are motorway miles. The car is very rarely used for short (less than 30 minutes) trips and I assumed that because of this, normally the DPF would be regenerated passively as the engine would surely be up to temperature. However, every 2 or 3 days at the end of a 75 to 90 minute trip of 70 miles back from the office, I pull up and an active regen is going, which doesn't make sense to me.

 

Is there any set frequency for this to happen? Is it after x miles and I just happen to be stopping at the due time and also, does the car just regen at the exact point required or should it have the intelligence to wait for so many miles until it gets to temperature in a journey, and only run the active regen if that doesn't happen? I'm sure there's no issue but I had a 2013 2.0 litre Octavia estate in my last job, doing similar mileage and journeys and I didn't notice this happening on this frequency.

[MoggyTech]

Sounds normal. I had a 2.0CR VRs and it insisted on doing regens every 400 miles, usually after coming off a motorway. Is the regen light coming on? if not it's a passive regen. The car is programmed to do these after set number of miles, regardless of the actual soot level in the DPF.

 

If you know someone with VCDS, they could check the soot level just to be safe. The latest VW DPF systems are pretty robust. Motorway cruising actually reduces EGT due to constant speeds and high airflow, so the car won't passive regen on the motorway.

[DickyG]

Thanks. Not sure whether the light is coming on or not: I haven't noticed it but that doesn't mean it isn't. I never knew that about motorway driving so that would mean it's unlikely the car is doing a passive regen as often as I assumed.

 

Cheers for the advice: much appreciated.

[S00perb]

16 minutes ago, MoggyTech said:

Is the regen light coming on?

I didn't know there was a regen light. Do all TDI models have it?