E91 330D - DPF issues lurking?

[Tony B2]

My wife’s E91 330D has been mechanically perfect to date, now around 64k miles.

I wonder, however, whether a DPF problem is about to raise its head - just in time for its MOT?

Symptoms are:
- a gradual increase in fuel consumption. Long-term consumption had always been around 36 to 38mpg, depending on use, sometimes getting into the 40s. Currently however, the consumption is 33mpg, over several thousand miles. Most of its use these days is on the M27, with multiple speed cameras, so it has spent a lot more at 70, on cruise control, than it ever used to in earlier days. The swingometer spends a lot more time in the low 30ish zone, whilst cruising.
- it doesn’t feel as lively as it used to, when my description of it was typically “effortlessly quick”. Now I am definitely more aware of the need for more throttle, to maintain progress.
- I do notice fairly often, some unexpected holding of lower gears (6-speed auto) which could be the DPF regen process, I guess?

There are no warning lights on display.

If it is a semi-clogged DPF, are any of the specialists who provide cleaning services any good?

[twokcc]

I have an 2009 E91 325d(3 litre engine).now on 83k
Used to have same concerns about mine only do a low mileage approx 4k p.a. but it seems to be very rare for these cars to get clogged DPF's from what I've seen on internet over last 9 years.

Even so was a post on the old BMWland about clearing these with an OBD reader
Plug in take car for a run and keep clearing error code and it will regenerate .itself.
Certain criteria have to be met- from memory engine upto correct working temp. and more than quarter tank of fuel
I have a Creator C110 code reader C110 will show engine temperature and also has a read out of exhaust back pressure(or similar name) so can check thermostats and DPF condition.
When I bought mine at 44k miles both thermostats required replacing- no problems since,

My 325d felt very similar to yours over last month I've just put it down to colder weather (and even less usage than normal)

HTH

Edited by twokcc on Monday 1st January 18:39

[Tony B2]

twokcc said:

I have an 2009 E91 325d(3 litre engine).now on 83k
Used to have same concerns about mine only do a low mileage approx 4k p.a. but it seems to be very rare for these cars to get clogged DPF's from what I've seen on internet over last 9 years.

Even so was a post on the old BMWland about clearing these with an OBD reader
Plug in take car for a run and keep clearing error code and it will regenerate .itself.
Certain criteria have to be met- from memory engine upto correct working temp. and more than quarter tank of fuel
I have a Creator C110 code reader C110 will show engine temperature and also has a read out of exhaust back pressure(or similar name) so can check thermostats and DPF condition.
When I bought mine at 44k miles both thermostats required replacing- no problems since,

My 325d felt very similar to yours over last month I've just put it down to colder weather (and even less usage than normal)

HTH

Edited by twokcc on Monday 1st January 18:39

Thanks for responding.

I will be using my Torque/OBD reader when I have some time to spare, after the holiday “break”, to check for errors, and also my BMW Drive Analyser, to see whether any diagnostic insight is forthcomimg

[wombleh]

Doesn’t sound like DPF, if it’s stopped regenerating then you’d get engine fault light and particle filter error message on idrive (if you have one) after about ten failures. I don’t think there’s a halfway house where you get some problems without the alerts, it either regens or doesn’t.

My understanding is that the limp mode is a massive loss of power, like struggling to get above 40mph, not just a slight drop. My E61 didn’t go into limp when the DPF was playing up, but did have faulty messages/lights.

There’s a hidden diagnostic menu where you can check it’s getting up to temp, worth looking up how to do that and change thermostats if it’s not getting hot. They ought to be service items as seem to die after 80-100k miles and stops DPF regen.

Edited by wombleh on Monday 1st January 19:20

[Tony B2]

wombleh said:

Doesn’t sound like DPF, if it’s stopped regenerating then you’d get engine fault light and particle filter error message on idrive (if you have one) after about ten failures. I don’t think there’s a halfway house where you get some problems without the alerts, it either regens or doesn’t.

My understanding is that the limp mode is a massive loss of power, like struggling to get above 40mph, not just a slight drop. My E61 didn’t go into limp when the DPF was playing up, but did have faulty messages/lights.

There’s a hidden diagnostic menu where you can check it’s getting up to temp, worth looking up how to do that and change thermostats if it’s not getting hot. They ought to be service items as seem to die after 80-100k miles and stops DPF regen.

Edited by wombleh on Monday 1st January 19:20

Do you know what the normal operating temperature should be?

I definitely need to investigate more on this - I came across one of my expenses/miles spreadsheets the other day, when I was using the car for longer journeys (but much faster ones...) and it was regularly providing over 43mpg.

Now at 32.x, so, even though a greater portion is at lower/town speeds, the faster/longerjourney miles are very much more "compliant" since the imposition of so many speed cameras on regular routes.

[easy_]

Following this, I too have experienced a notable drop in mpg from mid 40's to mid 30's despite my journeys remaining near enough the same.
I also feel the hot air coming out of the vents has dropped off a bit so wondering if thermostats are the issue..
Will check the temp the next journey I do.

[Martyn76]

EGR Thermostat opens at about 88-91 degrees I think.

[sortedcossie]

I'd be getting both stats changed, ours did the exact same.

Our independent garage that services ours will only use genuine thermostats, they had too many fail within a year or so from even decent non gen brands.

[wombleh]

I think you need it at 90 degrees for DPF to regen, plus a certain amount of fuel in and to be going over a certain speed (50mph ?).

[Tony B2]

wombleh said:

I think you need it at 90 degrees for DPF to regen, plus a certain amount of fuel in and to be going over a certain speed (50mph ?).

I have noticed in the last week or 2 that the auto box has been holding onto 2nd gear quite a long time when accelerating gently, and also when lifting off.

Up around 2800-2900 revs, and I have not noticed this before, except when on long downward stretches.

Could that be re-gen in action?

[twokcc]

Tony B2 said:

I have noticed in the last week or 2 that the auto box has been holding onto 2nd gear quite a long time when accelerating gently, and also when lifting off.

Up around 2800-2900 revs, and I have not noticed this before, except when on long downward stretches.

Could that be re-gen in action?

Mine doing the same and mpg reduced by about 4mpg the giveaway tho is very hot metal smell when I got out of car(in my garage). Looks as if I've stopped process couldn't continue to run it at time. Planning to go long way round on next journey just to get engine up to temperature again.