[DervJim]

Hey guys

Just recently had a load of problems due to DPF which it turns out has been down to the thermostats both being knackered (yesterday a 15 mile drive to work at 40-50mph only got up to highest temp of about 69C).

Seems a common issue and has presumably prevented the DPF from regenerating, probably for some time. Most of my driving is low ish speed sadly and fairly short trips, and no motorways near me at all - not what a diesel wants.
I've done forced regens via Carly app, and the soot claimed to have dropped from 45g to 16g, but almost straight after was right back up there again, so I don't think it really worked.

Anyway, since the DPF became an issue the car has been intermittently horrific off the halt sign, and below 2000rpm, ie if you apply any load with the throttle it bogs right down as if it'll stall, but when it gets to about 2000 and boosts properly it picks up fine.

I assumed this was due to the DPF issues but then on one occasion found a MAF fault. I've only seen it once so far, but this morning I unplugged the MAF and it drove just great. Didn't bog down once at all, and went really well.

Now know doing this is a fair way to know the maf is failing if you disconnect and the car runs better but it was perfect until the DPF issue came up last week, and is only 3 months since I fitted a new Bosch Maf to it anyway.

Could be complete genuine coincidence that it's failed prematurely and right the same time as the DPF issues I've got (and all 6 glow plugs (or more likely the controller) too), but just seems a bit suspect. Can't see any way really that a Maf could be affected by faults further down the system on the exit side of the gases, but who knows.

Interested in thoughts (while I await arrival of new thermostats etc).....

Cheers!

[rasa bmw]

could the maf of gotten oil(mist) or any kind of contamination form a goosed dpf? just a thought,mafs hate any kind of soiling.

[DervJim]

Thanks mate

Not really feasible at all as far as I can see though as the Maf is on the inlet side and the DPF is in the exhaust. Shouldn't be any physical way that's possible as far as I can think.
You're absolutely right about them hating any grime whatsoever though.

Maybe the maf has just genuinely failed at the exact same time as the DPF issue and only about 3 months old, but it just all seems like a bit much of a coincidence. I can't see how it could be linked at all, but maybe someone else has had something similar....

Got new thermostats to fit now anyway as it's only getting up to between 60-70C on a 15 mile drive unless you beast the car, and the DPF is gonna have to come out too.

Lots of time & money & ground up knuckles for me then!

[rasa bmw]

Originally Posted by DervJim

Thanks mate

Not really feasible at all as far as I can see though as the Maf is on the inlet side and the DPF is in the exhaust. Shouldn't be any physical way that's possible as far as I can think.
You're absolutely right about them hating any grime whatsoever though.

Maybe the maf has just genuinely failed at the exact same time as the DPF issue and only about 3 months old, but it just all seems like a bit much of a coincidence. I can't see how it could be linked at all, but maybe someone else has had something similar....

Got new thermostats to fit now anyway as it's only getting up to between 60-70C on a 15 mile drive unless you beast the car, and the DPF is gonna have to come out too.

Lots of time & money & ground up knuckles for me then!

had my stats done couple of months ago,and i aint got a dpf,got it out with my map same time,i do lots of short journies as its a weekend car.i use my e46 330d sport for a dialy and just done the main stat yesterday actually,and new waterpump and coolant change

[DervJim]

Yeah mine is all short journeys too so it's a problem for me.

Well I got the DPF taken care of over the weekend, but as soon as it was all back together again, I instantly have got errors on the seatbelts and airbags, and the control buttons on my steering wheel have stopped working.

Sure this can't be a coincidence either. Maybe I disturbed a wire or connector while the car was jacked up or while I had steering rack disconnected from the steering column to make room for the DPF etc??

[rasa bmw]

taken care of? if ypu mean you took it off/out,then thats not a good idea,it will nedd programming out ..have a read of bmw chiptune on the cars he has had with dodgy removal attempts,,ive kjust seen one on (durham remaps) website,they got a car in that had had a remap and dpf removal..dear me stevie wonder would have done a better job,,and the car was in limp mode and throwing loads of codes.

[DervJim]

Yeah it's removed (no annual MOT to be concerned about where I live and no motorways/difficult to get a good run for it to regularly do regens etc).
It's arranged with a mapper to be deleted from the ECU though yes.

I'm going to try INPA etc instead of the carly app to see if it gives any additional info on these errors, or does a better job clearing them potentially.

[andy101]

Can I ask how you knew if both stats were knackered or just the pre dpf one?
Having loads of issues with my E91.

[Grainqey]

In response to the maf issue, was it bought from an genuine Bosch supplier distributor or was it bought from such as eBay or eurocarparts?

If it is the latter then I've had experience of eBay purchases (Bosch lambda sensors) and eurocarparts maf sensors and thermostats, they seem to be seconds/rejections from QC and I've had to purchase genuine dealer replacements to guarantee them working/lasting without intermittent faults and actually working correctly

Hopefully you get to the bottom of your problem.

[rasa bmw]

Originally Posted by andy101

Can I ask how you knew if both stats were knackered or just the pre dpf one?
Having loads of issues with my E91.

stats?pre dpf?stats are located on front of engine,and to know they are knackered you have to run a water temp test via hidden menu..or are you confusing stats with cats?

[Len_Beach]

A MAF fault will stop the DPF regenning.

Look on the MAF itself and there should be various part numbers. Search ebay for these and you should be able to pick up a bargain.

I bought a MAF for my 330d LCI for £20 searching purely for these numbers rather than the BMW part number.

[rasa bmw]

Originally Posted by Len_Beach

A MAF fault will stop the DPF regenning.

Look on the MAF itself and there should be various part numbers. Search ebay for these and you should be able to pick up a bargain.

I bought a MAF for my 330d LCI for £20 searching purely for these numbers rather than the BMW part number.

yeh,but the after market sensors are usually buy cheap buy twice,same as most parts like thermostats.

[DervJim]

Originally Posted by Grainqey

In response to the maf issue, was it bought from an genuine Bosch supplier distributor or was it bought from such as eBay or eurocarparts?

If it is the latter then I've had experience of eBay purchases (Bosch lambda sensors) and eurocarparts maf sensors and thermostats, they seem to be seconds/rejections from QC and I've had to purchase genuine dealer replacements to guarantee them working/lasting without intermittent faults and actually working correctly

Hopefully you get to the bottom of your problem.

Sorry, only just noticed these replies!

It was from an ebay seller and sent from Germany.
I think maybe you're right about the quality potentially. Pretty certain it's not fake as I'm fairly good at spotting them and everything is identical to the original, down to the texture of the plastic, all the marks etc etc.
It does make sense that possibly they're questionable QC ones though as you've suggested.

Was perfect for a few months but it makes the car barely driveable suddenly. Not sure if I'll be able to get any comeback on it since it was ebay and you can't do anything after 2 months but I'll try....

Hard to know where's the best price for a guaranteed genuine one though I guess. I don't have money to throw about and the car's just cost me quite a bit recently. Think the one I bought was £130 anyway.


Anyway, I've just replaced both thermostats today and the temperature is at least fine now, whereas it was only going to about 60-70C last week unless it was given a lot of stick. Pretty sure that's what caused the DPF to block up because it wasn't getting up to normal temps and the maf was only a very recent thing.

I have now got a fault code for the steering wheel as well as airbags and seatbelts. I'm quite certain these faults are all down to either the clock spring or the steering angle sensor, although I presume the sensor would give its own fault if it had failed so my money is on the ribbon cables in the clock spring.

[Len_Beach]

Originally Posted by rasa bmw

yeh,but the after market sensors are usually buy cheap buy twice,same as most parts like thermostats.

I bought a functioning second hand part. I'd never buy third party for the reasons you've stated.

[Grainqey]

Originally Posted by DervJim

Sorry, only just noticed these replies!

It was from an ebay seller and sent from Germany.
I think maybe you're right about the quality potentially. Pretty certain it's not fake as I'm fairly good at spotting them and everything is identical to the original, down to the texture of the plastic, all the marks etc etc.
It does make sense that possibly they're questionable QC ones though as you've suggested.

Was perfect for a few months but it makes the car barely driveable suddenly. Not sure if I'll be able to get any comeback on it since it was ebay and you can't do anything after 2 months but I'll try....

Hard to know where's the best price for a guaranteed genuine one though I guess. I don't have money to throw about and the car's just cost me quite a bit recently. Think the one I bought was £130 anyway.


Anyway, I've just replaced both thermostats today and the temperature is at least fine now, whereas it was only going to about 60-70C last week unless it was given a lot of stick. Pretty sure that's what caused the DPF to block up because it wasn't getting up to normal temps and the maf was only a very recent thing.

I have now got a fault code for the steering wheel as well as airbags and seatbelts. I'm quite certain these faults are all down to either the clock spring or the steering angle sensor, although I presume the sensor would give its own fault if it had failed so my money is on the ribbon cables in the clock spring.

No worries!

It sounds like you're starting to get on top of your issues!