BMW E90 DPF question

[triggerhappy21]

I've been having the usual DPF woes with my E91 335d.

It's been in the garage a couple times, new glow plugs, new battery and that seems to sort it for a while.

This week I got the DPF warning light again, so got myself a bluetoothe OBD2 adaptor and Bimmer-tool app on my phone. Went out for drive, successfully cleared codes and forced regen, but I've got some questions on the figures.

My ash mass is 1.8g.
My soot mass is over 60g, which appears over 100%.

When it regen'd, the soot mass dropped slowly to around 50%. As I slowed car near home, the level shot straight back to 100% within a minute or so. At home, the DPF error (480A) is back.

I suspect this isn't normal behaviour, is anyone familiar with above?

[E-bmw]

IMHO the answer is quite simple, get the DPF removed & cleaned properly or replaced and then get the engine diagnosed correctly to find out what is the issue causing the DPF blockage. It could be any one of many issues causing it and from here we will never even be able to guess which it is.

[triggerhappy21]

E-bmw said:

IMHO the answer is quite simple, get the DPF removed & cleaned properly or replaced and then get the engine diagnosed correctly to find out what is the issue causing the DPF blockage. It could be any one of many issues causing it and from here we will never even be able to guess which it is.

The glow plugs had an error on them stopping the regen for quite a while. I suspect that blocked the DPF more than a regen can clear.

You're absolutely right. I'll look into the best way to get it properly cleaned.

[Demelitia]

triggerhappy21 said:

E-bmw said:

IMHO the answer is quite simple, get the DPF removed & cleaned properly or replaced and then get the engine diagnosed correctly to find out what is the issue causing the DPF blockage. It could be any one of many issues causing it and from here we will never even be able to guess which it is.

The glow plugs had an error on them stopping the regen for quite a while. I suspect that blocked the DPF more than a regen can clear.

You're absolutely right. I'll look into the best way to get it properly cleaned.

Wynns off car DPF cleaner seems to be getting pretty good reviews, although I’ve no personal experience with it.
It could be worth a shout given it’s reasonable cost.

[twokcc]

The glow plug problem will have prevented the regeneration now fixed car is attempting to regen. Used to be a good thread on the old BMWland website about getting dpf to regenerate with a creator C110 code reader. Had similar problem to yours with code repeatedly coming back. He took it for a very long run with passenger to keep clearing the codes as they appeared. From memory car needs to have more than quarter tank diesel and thermostats have to be getting engine upto temperature. May be worth trying this with yours less than £100 to fill tank up -just keep clearing codes and keep going

[triggerhappy21]

Thanks for the responses. Had a bit of an update on this.

As suggested, I think the 2 years of glow plug errors stopped the regen, and did a real number on my DPF.

Initially it was struggling to get the soot mass down. Then after about 1hr at motorway speed, forcing regen the whole time, the regen really kicked in. Shot up to well over 600degc and soot mass plummeted. The app was useful as it periodically cleared the codes for me, while forcing regen.

No fault codes coming back in week since, and regen seems to be merrily activating itself when required.

Chuffed with result, certainly saved a bit of back and forth with garage to get resolved.

Edited by triggerhappy21 on Saturday 26th February 13:43

[stevieturbo]

triggerhappy21 said:

Thanks for the responses. Had a bit of an update on this.

As suggested, I think the 2 years of glow plug errors stopped the regen, and did a real number on my DPF.

Did you not try and get it fixed before 2 years ?

[GreenV8S]

triggerhappy21 said:

I think the 2 years of glow plug errors stopped the regen

I have no idea whether a glow plug error would prevent a regen but I'm curious to know why it would. I'd have thought glow plugs would be unused after the initial start, and the regen would only happen under sustained load when hot.

[triggerhappy21]

stevieturbo said:

Did you not try and get it fixed before 2 years ?

Glow plugs were flagged up at service 2019. Garage mentioned they weren't critical and to book in to get sorted whenever. Didn't mention they stopped the regen. Then with COVID MOT delays, it was 2021 before it was back in garage. That was around the same time it started putting up emissions warnings.

Car was running fine for those 2 years, no warnings or anything. If I'd read the faults I would have seen the codes, but nowt came on dash. DPF was just getting f**ked without me knowing.

[stevieturbo]

GreenV8S said:

I have no idea whether a glow plug error would prevent a regen but I'm curious to know why it would. I'd have thought glow plugs would be unused after the initial start, and the regen would only happen under sustained load when hot.

glow plugs are used at various times, not only for starting. Most are not a simple off on, but PWM controlled for both fast initial heating, plus reduced longer duration heating.

And I've heard before that yes faulty glow plugs can prevent re-gens



https://www.denso-am.co.uk/news/latest-news/2019/d...

Edited by stevieturbo on Saturday 26th February 21:32