Regens

[Lobster Pot]

Finally got it doing regens today took it in to my Indy to have a full software update and all and behold it’s worked took some cleaning about 5 regens as it was at 80g but after about 1.5 hours drive it come down to 1.3G just got to keep a eye on it now and see what happens
Anyone know if there’s any actual figures it starts and stops the regen ?

[X5Sport]

The system uses a combination of exhaust back pressure and distance travelled (maximum 600 miles between regens). Frequent shorter journeys pull the regen frequency higher (every 250-400 miles) but very short journeys mean the exhaust gas temp (EGT) won’t exceed the burn-off startup threshold (it needs to rise to 240°C) and results in a clogged DPF. That brings a warning light on and inhibits further regens unless cleared. Coolant temps below 75°C also inhibit regens. A regen raises the EGT to above 00°C (hence the fans running in high).

Minimum speed is 38mph for 20-30 mins. Ideally, according to the TIS, the speed should be around 62mph. If fault codes 480A (back pressure too high) or 481A (back pressure above maximum) are recorded, then the drive time increases to at least 50 mins at 60mph.

DPFs also have a maximum service life based on distance travelled and pattern of use. Once exceeded warning messages appear. Only a reset or replaced DPF will work. The service life is based upon the expected life of the platinum catalyst. The TIS doesn’t state the figures though.

[Lobster Pot]

I’ll just keep a eye on it and see what happens it hadn’t done one for 16k miles I’m just happy it’s finally doing them at last

[Leslie]

DPF counter service life is 250,000 kilometres, approx 150,000 miles from what I've read and that's what mine showed after reset x5 e70

It may not have done a complete regen in 16k but it certainly must have done passive regens or it would have ground to a hault long ago imo.

[Lobster Pot]

It was more the grams info I was after as I wasn’t sure after the regen if 1.3G was right after it finished or if it should go to zero
I couldn’t tell you if it’s done passive or not according to dpf info it was 16k miles ago I’ve done 7k in it since I’ve had it and it’s not done one while I’ve had it and I’ve done quite a few motorway trips in it

[Leslie]

1.3 grams is empty virtually nothing in there, it's a calculation based on back pressure inside as it's not possible to measure the actual soot mass.
Passive is where if it gets hot enough it will clean itself out to some degree or it will block rather than a computer controlled active regen.The computer won't have asked for it or be aware it is happening so counter won't reset. Without either I doubt it could get much past say 1000 miles at a guess before the engine would be strangled by a blockage if there is usually one every 300 mile or so.

[sapphireblack]

I am intrigued by this subject. Is there a tell when the car performs this action? My X6 is somewhat underused, but i do periodically take it for a sustained motorway run in excess of 40mph. I've never noticed or felt anything happening that would lead me to think a regen is happening.

[Lobster Pot]

I was sat at motorway speed if wasn’t for having my app running you would never have known it was happening

[sapphireblack]

Ah, so no indications when happening, visual, audible or even physical

So my machine may have done this without my knowledge, i imagine by BMWs design?

[Lobster Pot]

At lower speed you may hear something not sure some have stated fans run faster but mine was running normal speed when I pulled off motorway to turn round only thing I can say I noticed is I used quarter tank of fuel in the process
Best thing to do is hook up a scanner to you can see what’s happening and if possible request regen and see if it happens

[X5Sport]

The only way that I know for certain is when pulling up and switching off, the engine fan runs on at full speed for several minutes. It’s all supposed to use a bit more fuel, but I’ve never noticed a significant change whilst driving.

[Leslie]

A slight smell of burning when you get out after a run when you get out would be as near as I could guess a regen has been happening ,a good run out once a week where I put it ii sport and keep the revs at 2k for 5 miles after a 5 mile warmup and then a few easy miles after will give it a good clearout if the car decides its needed as I do quite a few 4 mile runs which is far from ideal so soot builds fast.

[sapphireblack]

Thanks. Numerous points to mentally note for the future. It all seems pretty lo-tec for something that can be costly if it goes boobies up

[Alan Gunn]

And a Thanks from me as well.
Just got a dpf fitted car but i only do short runs now 9 mile the 9 back.
Wife had one some years ago but that got the long runs so never any problem.
Will be listening/watching but no sense of smell for the burning bit lol.

[Lobster Pot]

Just get a scanner that can read dpf it will tell you when last one was plus engine temp exhaust temp back pressure and can also request a regen and see when it’s running