Hi all,

As the titile suggests...anyone else had this? Never happened to me before, not driven the car in 2 days, just started it and it went straight into a regen!

How do you know it went into regen?

First junction I pulled up to the car was idling around 1k RPM - that's what it does in regens. Didn't have the air con on either, so couldn't have been that.

Not straight after a cold start, but had one last week after just two miles, on my three mile commute home. Oil temp was only 82C when stopped, having only been 60 or so when I noticed the regen had kicked in, and the fans did their thing for five minutes once parked. I've also noticed them a few times in winter when the oil temp hasn't even reached the 50C point. Up to now I've never had the DPF light come on (just over 48K), so quite why it's so keen I don't know!

Yeah mine seems to do an awful lot of regens - and is the only diesel car I have ever had that does it noticeably too...F20 1 Series and new Mazda 6, never ever noticed them doing a regen at all!

While a regen causes an idle of 1000rpm, an idle of 1000rpm doesn't mean it is doing a regen.

 

You say it hadn't moved for two days, maybe the battery voltage dropped and it was recharging it.

 

Did you have the heating on? I bet that could make it idle quicker to produce more hear for the cabin.

Nope, no heating on - it was quite warm outside. It was definitely doing a regen, as when I stopped there was the usual smell / fan still on.

Previously owned a 2015 vrs diesel..loved the torque etc..and lovely car but due to my low mileage and short drives ..i had constant regens and light on dash requiring the 20 min drive down the motorway at 2000 revs plus..so got rightly sick of this so traded it in for the newer petrol 230 vrs ..oh the joys ...no more dpf to worry about.and lovin the 230vrs

Edited 17 May, 201610 yr by dubhman284

A high RPM at idle isn't always a regen.

 

Battery drain and the demands of the climate control can all increase the engine RPM.

 

The fans running on after the engine is turned off is a sure sign of an interrupted regen though.

 

Things might have changed on the MkIII but a regen should not commence until the engine is up to operating temperature. Remember that the whole idea of the increased RPM is to generate heat, on a cold or warming engine there is little point attempting a regen, there won't be enough heat available.

Yeah it was definitely a regen - as it hadn't quite finished when I stopped so let it idle for a couple of mins and then the stop start kicked in when it had finished - accompanied by aforementioned smell and fan remaining on. May be just a one off!

Yeah it was definitely a regen - as it hadn't quite finished when I stopped so let it idle for a couple of mins and then the stop start kicked in when it had finished - accompanied by aforementioned smell and fan remaining on. May be just a one off

 

A DPF regen can only work at high temperature. If this tried to regen from a cold start you have issues. Cant see how it can even try from low temps. It would be impossible.

I don't understand why you think its not feasible for the car to be doing a regen.

 

It needed to do a regen due to the DPF being partially blocked so it did one. It doesn't care that you havn't driven it for 2 days, on the previous run it must have just been on the edge of needing to do one so it decided it was time. 

I don't understand why you think its not feasible for the car to be doing a regen.

It needed to do a regen due to the DPF being partially blocked so it did one. It doesn't care that you havn't driven it for 2 days, on the previous run it must have just been on the edge of needing to do one so it decided it was time.

Yeah exactly, just never experienced it starting the process when the engine is still cold! It was definitely happening though!

Yeah exactly, just never experienced it starting the process when the engine is still cold! It was definitely happening though!

Like everybody has said above, the initial high idle was the car trying to warm itself up as fast as possible due to a number of reasons and possibly because it wanted to do a regen. The regen process will of only started when the coolant temp got to a reasonable level because as we all know, the set parameters in the ECu won't allow a regen to take place on a cold engine.

mines done it before. usually when the region didn't finish from the last time I turned it off.  it realises it needs to do a region so sticks a load on the car and tries again.  I think 3 restarts was my max and at that point I took it for a good run to clear it.