M340d 3rd time engine light on - DPF sensor

M340d 3rd time engine light on - DPF sensor

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Mafioso

Original Poster:

2,360 posts

217 months

Monday 5th February
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Anyone else suffering like me and my father with his? Both of ours have been in twice under warranty for replacement DPF sensors. My engine light has come on again today. It's a 21 plate on 20k miles (he's on about 12k). Admittedly I do a 5 minute commute most days but it gets a good run most weekends. I've had diesels for over 10 years now and never experienced this. Just wondering what to do going forwards as I love the car...?

McGee_22

6,877 posts

182 months

Monday 5th February
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Modern diesels don't like 5 minute drives - I would suspect the effects of that are what's bringing the light up.

bigdom

2,097 posts

148 months

Monday 5th February
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A mate lent out one of his cars recently to a friend in need, who appears to have driven similar to you for a month. The day after it was returned, the DPF light came on. BMW fixed it, advised premium diesel/additives help, but won't cure.

That's a journey for an electric car, walking, bike etc. No combustion engine will enjoy that trip, too short, not hot.

_Hoppers

1,281 posts

68 months

Monday 5th February
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From the OP’s post the problem doesn’t appear to be a clogged DPF but a failed sensor.

bigdom

2,097 posts

148 months

Tuesday 6th February
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_Hoppers said:
From the OP’s post the problem doesn’t appear to be a clogged DPF but a failed sensor.
True, however they've suffered issues with these sensors, and one of the causes has been through condensation - I thought the new ones had solved the problem. Giving the driving profile, that seems likely to be part of the culprit on continued failures.

Mafioso

Original Poster:

2,360 posts

217 months

Tuesday 6th February
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Thanks for your replies. Do you have any reference to the condensation issues? There is nothing wrong with my DPF - it's just been a faulty sensor replacement every time. Maybe a faulty batch or something?

rassi

2,459 posts

254 months

Tuesday 6th February
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Have you also had a problem about the gearbox not going into 8th, and only stays in 7th even at higher speed?

Mafioso

Original Poster:

2,360 posts

217 months

Tuesday 6th February
quotequote all
rassi said:
Have you also had a problem about the gearbox not going into 8th, and only stays in 7th even at higher speed?
No I don't think so. Does it do this if it's doing a regen?

Ky

1 posts

2 months

Tuesday 21st May
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Hi, my 2022 plate had engine management light on which has been diagnosed as dpf sensor fault.
Just drove 500 miles in a day on Friday up north and back so wouldn't think actual dpf could be clogged. Let's see when I get it back. Currently with dealer now.

rottenegg

592 posts

66 months

Friday 24th May
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Ky said:
Hi, my 2022 plate had engine management light on which has been diagnosed as dpf sensor fault.
Just drove 500 miles in a day on Friday up north and back so wouldn't think actual dpf could be clogged. Let's see when I get it back. Currently with dealer now.
There are 6 sensors in the DPF. 2 x oxygen sensor, 2 x pressure sensor and 2 x temperature sensor. Let's hope they diagnose it correctly and don't throw all 6 at it.

Mafioso said:
rassi said:
Have you also had a problem about the gearbox not going into 8th, and only stays in 7th even at higher speed?
No I don't think so. Does it do this if it's doing a regen?
On some versions of 8HP, 8th isn't selected in sport mode. If it doesn't engage in comfort, there's either a mechanical fault or not enough oil in the transmission.

Mafioso

Original Poster:

2,360 posts

217 months

Thursday 6th June
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Ky said:
Hi, my 2022 plate had engine management light on which has been diagnosed as dpf sensor fault.
Just drove 500 miles in a day on Friday up north and back so wouldn't think actual dpf could be clogged. Let's see when I get it back. Currently with dealer now.
How did you get on?

richyd

297 posts

230 months

Friday 7th June
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My 2022 M340d has just been diagnosed with the same problem. BMW Assist came out and diagnosed it on my driveway, faulty DPF sensor.

Going in to dealer in 2 weeks to have the replacement part fitted.

Mafioso

Original Poster:

2,360 posts

217 months

Tuesday 18th June
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richyd said:
My 2022 M340d has just been diagnosed with the same problem. BMW Assist came out and diagnosed it on my driveway, faulty DPF sensor.

Going in to dealer in 2 weeks to have the replacement part fitted.
What sort of driving do you do? I just think this is something that will happen every year with mine...

joropug

2,642 posts

192 months

Tuesday 18th June
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Have you read the codes yourself ? Carly is great for this.

My 2020 520d had an EML on when I bought it, BMW were tasked with diagnosing and fitted a DPF sensor (57k). The day after I collected the car the EML came back on, then went off. A few k later it started coming on intermittently then permanently as the NOx sensor. There were 4 related codes.

There might be more than one faulty sensor. They are not cheap. The NOx was £450 for the part alone which blows my mind. Luckily the supplying dealer was still on the hook for it.

I do a number of short journeys too but usually get up to temperature. On the weekends I tend do longer drives and have had multiple diesels with no issues.

DJMC

3,466 posts

106 months

Wednesday 19th June
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When we buys these cars new are we told "Oh, and by the way you can only do certain types of driving, and also your car may catch fire due to us putting in a plastic intake manifold after years of metal ones."

No.

Design fault I say.

Class action.

richyd

297 posts

230 months

Wednesday 19th June
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Mafioso said:
richyd said:
My 2022 M340d has just been diagnosed with the same problem. BMW Assist came out and diagnosed it on my driveway, faulty DPF sensor.

Going in to dealer in 2 weeks to have the replacement part fitted.
What sort of driving do you do? I just think this is something that will happen every year with mine...
Mine is mixed driving. 300 miles last Saturday with some bumbling around town during the week. It was the sensor that failed, not a clogged DPF.

Sensor replaced today under warranty. 3 hr job including the wash and hoover

rottenegg

592 posts

66 months

Saturday 22nd June
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DJMC said:
When we buys these cars new are we told "Oh, and by the way you can only do certain types of driving, and also your car may catch fire due to us putting in a plastic intake manifold after years of metal ones."

No.

Design fault I say.

Class action.
The 40 and 50Ds have a metal intake.

Blame Brussels, not BMW. They forced all these emission controls onto all car manufacturers but didn't mandate simple and cost effective maintenance of said components. £2K for a DPF, £500 for an EGR cooler, £250 for an EGR valve, £700 for a plastic intake, £300 O2 sensors, silly money EGR temp sensors, silly money DPF differential pressure sensors etc etc. All priced according to importance....i.e. the engine won't run properly without said emissions controls, forcing you to comply and cough up, or have a sht running car.

This is why people gut DPFs and remap engines to code out the EGR.

Petrol turbo engines are no longer allowed to add fuel enrichment in boost either, hence why there are so many hybrids now, further adding to the spiralling maintenance merry go round.




Mafioso

Original Poster:

2,360 posts

217 months

Wednesday 26th June
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richyd said:
Mafioso said:
richyd said:
My 2022 M340d has just been diagnosed with the same problem. BMW Assist came out and diagnosed it on my driveway, faulty DPF sensor.

Going in to dealer in 2 weeks to have the replacement part fitted.
What sort of driving do you do? I just think this is something that will happen every year with mine...
Mine is mixed driving. 300 miles last Saturday with some bumbling around town during the week. It was the sensor that failed, not a clogged DPF.

Sensor replaced today under warranty. 3 hr job including the wash and hoover
Yep, pretty much exactly the same as me. Lots of pootling around town but plenty of regular long motorway journeys too. never had a problem with any of my other diesel cars (with PDFs)...