[John320d]

Hi guys, I have had my 320d E93 since new in 2008, it has now got 32k miles on it. For the last 2 years it has only been used as a shopping trolley doing 6 x 1 mile journeys per week. The dreaded DPF warning light has now come on. Will a thrashing on the motorway possibly clear it, and if does clear it will the warning cancel itself. We used to have a little Seat in the family and the engine management light would come on every year just before MOT time, I would thrash it and cancel the warning light with a cheap gizmo, and then it was good to go for another year. Cheers.

[Tambohamilton]

No thrashing required, but yes a long(er) drive at a decent speed is needed.

What the regen needs is for the engine to be up to operating temp, then driven at a steady pace (regen pauses at WOT) for a while so it can get the dpf up to temp and begin regeneration.

I'd say a warm up, then an hour at 70ish cruise on the motorway to let it do its thing. Maybe it'll take longer because it's more clogged than mine's ever been (mine seems to regenerate in about half an hour of motorway driving, though I've never logged it). Drop to 5th (~2000rpm) if you feel like it, since a slight raise in revs won't hinder anything. But there's no need to have it screaming, and hard acceleration actually inhibits the regen.

If that doesn't help, you should probably check for error codes to make sure there's nothing wrong which could prevent an active regen. And you should check using the hidden menu in the OBC to make sure it is getting up to operating temp as it should.

[John320d]

Thank you for your reply, what are the signs that a re-gen is taking place.

[Tambohamilton]

The engine will run a bit hot (only noticeable if you're looking at temps on the hidden menu), and fuel consumption will increase. If you're sensitive to that kind if thing, you may also notice the engine running a bit rougher than usual; nothing crazy, just not quite right.

You can watch things happen via INPA, I believe, but I've never spent time to work out how... And it's not advisable unless you have an assistant/driver.

[rasa bmw]

as above,,but im yet to notice a regen happening on my 335d,,im usually concentrating driving,,yup im that sensible a driver,,90% of the time anyway ha ha

[Diawal91]

Originally Posted by Tambohamilton

No thrashing required, but yes a long(er) drive at a decent speed is needed.

What the regen needs is for the engine to be up to operating temp, then driven at a steady pace (regen pauses at WOT) for a while so it can get the dpf up to temp and begin regeneration.

I'd say a warm up, then an hour at 70ish cruise on the motorway to let it do its thing. Maybe it'll take longer because it's more clogged than mine's ever been (mine seems to regenerate in about half an hour of motorway driving, though I've never logged it). Drop to 5th (~2000rpm) if you feel like it, since a slight raise in revs won't hinder anything. But there's no need to have it screaming, and hard acceleration actually inhibits the regen.

If that doesn't help, you should probably check for error codes to make sure there's nothing wrong which could prevent an active regen. And you should check using the hidden menu in the OBC to make sure it is getting up to operating temp as it should.

+1

[Silver Streek]

I never notice mine doing a regen either, but i do drive on the motorway as part of my commute home so the car get a steady 70mph or so for 40 mins every week day.

[Tambohamilton]

Even if an active regen isn't triggered by the DPF pressure sensor(s), they will still run on a schedule based on mileage, if I remember rightly. Something like 500mi between regens, regardless of whether or not they're requested.

[mjn77]

Also make sure your car meets all the conditions for a regen. i.e. more than a quarter tank of diesel, no failed glow plugs, engine gets up to temperature, etc

[Tambohamilton]

The failed glow plugs thing is a myth; my 330 has had at least one glow plug out (initially 5, currently 3) for the entire time I've owned it, and it definitely does active regens still.... Not that it's a bad idea to have your glow plugs fully operational!

[mjn77]

Originally Posted by Tambohamilton

The failed glow plugs thing is a myth; my 330 has had at least one glow plug out (initially 5, currently 3) for the entire time I've owned it, and it definitely does active regens still.... Not that it's a bad idea to have your glow plugs fully operational!

Not a myth. Had it two weeks ago. Cylinder 1 had a duff glow plug, no regens. As soon as it was replaced, regens started.

I have the error codes printed out.

[Tambohamilton]

Can you share the codes?

[mjn77]

Originally Posted by Tambohamilton

Can you share the codes?

Sure. Will upload them. Gimme a few mins.

[mjn77]

Here you go. Replacing the glowplug resolved tge issues.

[Tambohamilton]

Well, that is weird! 4212 is one of the codes that's been live on my car the whole 2 years I've had it. And I've done/do a lot of short trips which really necessitate the active regens... That and I'm pretty sure I can tell when it's doing it.

I wonder if different ECU versions or software could explain why yours needs all of its glow plugs, and mine doesn't care?

Anyhow, any progress, OP?

[mjn77]

My 335d is July 2011 build and all software is up to date.

[Tambohamilton]

Well mine's a 330d and I think still runs the software it left the factory with in 2007...

[John320d]

Thanks lads, everything is ok now with my dpf. I had a problem with the hidden memory, when I reached "lock off" I got no prompt what to do next and then when I tried to guess the next stage to "temp" the whole process just shut down.

[E60525d]

Originally Posted by mjn77

Not a myth. Had it two weeks ago. Cylinder 1 had a duff glow plug, no regens. As soon as it was replaced, regens started.

I have the error codes printed out.

Opposite experience on my N57 330d. I had 2 glow plug cylinder errors for about 6 months and DPF kept regenning. Was verified by ISTA which showed regenerations were happening.

[mjn77]

Originally Posted by E60525d

Opposite experience on my N57 330d. I had 2 glow plug cylinder errors for about 6 months and DPF kept regenning. Was verified by ISTA which showed regenerations were happening.

Different engine, so different behaviour is not unexpected.

[Tambohamilton]

Yeah, though it's interesting that there is a difference... Why is it that (seemingly) a 335 needs good glow plugs to regen, but a 330 doesn't? I'm sure someone's thought about it, but it's pretty strange!

[mjn77]

Originally Posted by Tambohamilton

Yeah, though it's interesting that there is a difference... Why is it that (seemingly) a 335 needs good glow plugs to regen, but a 330 doesn't? I'm sure someone's thought about it, but it's pretty strange!

Not sure, but it definitely means i have to regularly scan for error codes, when really, if a duff glow plug prevents DPF regen i should get an error light on the dash or in the idrive.