Need urgent advice with 335i Warranty Claim
Discussion
Evening guys,
Bit of a long one. I have a 59 plate DCT 335i (N54 engine).
i got the following codes
29E0 Mixture control
29E1 Mixture Control
The engine light came on but didn't appear to have any ill effects.
Right after i got 29F1 Fuel Pressure, Plausibility. With this code I was getting half engine light and reduced power.
I brought it into Stephen James Enfield as it has an extended BMW warranty. After nearly a week, they diagnosed it as being the fuel pump...fine. They changed this but also said that the car was still running a bit rough and the fuel mixture codes were still present with the light. Few days later they said they found a crack in my rocker cover which was causing a vacuum leak...fine. I got the car back and two days later the light was on with the fuel mixture codes. Took it back after a week or so of them ignoring my calls. This time it was the low pressure fuel pump sensor. They said car was still a bit rough but were happy for me to take it. I said i wasn't happy as its obviously not 100%. Anyway, I took the car back and the next day the light comes back on! Its now back in there again. They said my intakes are coked up and need cleaning (walnut blasting I assume?). They're not sure if this is the actual problem but say I have to pay as its classed as maintenance. I think its the injectors as the car is very lumpy on cold start and when moving off from cold it stumbles and acts like its going to stall. It is okay once warm but still bit lumpy on idle.
Does anyone have any tips or advice on how to deal with this as they seem to be treating this as an experiment. I have fairly newish coils and plugs (under 10k) and the car is stock.
Thanks a lot!
Bit of a long one. I have a 59 plate DCT 335i (N54 engine).
i got the following codes
29E0 Mixture control
29E1 Mixture Control
The engine light came on but didn't appear to have any ill effects.
Right after i got 29F1 Fuel Pressure, Plausibility. With this code I was getting half engine light and reduced power.
I brought it into Stephen James Enfield as it has an extended BMW warranty. After nearly a week, they diagnosed it as being the fuel pump...fine. They changed this but also said that the car was still running a bit rough and the fuel mixture codes were still present with the light. Few days later they said they found a crack in my rocker cover which was causing a vacuum leak...fine. I got the car back and two days later the light was on with the fuel mixture codes. Took it back after a week or so of them ignoring my calls. This time it was the low pressure fuel pump sensor. They said car was still a bit rough but were happy for me to take it. I said i wasn't happy as its obviously not 100%. Anyway, I took the car back and the next day the light comes back on! Its now back in there again. They said my intakes are coked up and need cleaning (walnut blasting I assume?). They're not sure if this is the actual problem but say I have to pay as its classed as maintenance. I think its the injectors as the car is very lumpy on cold start and when moving off from cold it stumbles and acts like its going to stall. It is okay once warm but still bit lumpy on idle.
Does anyone have any tips or advice on how to deal with this as they seem to be treating this as an experiment. I have fairly newish coils and plugs (under 10k) and the car is stock.
Thanks a lot!
Try another dealer ?
Get onto the BMW warranty team and challenge that SJ aren’t treating it as a warranty claim?
If you’re going to have to pay , shop around for a specialist.
I had same car , ran it to 85k miles , injectors only issue. But I’ve heard good things about walnut blasting.
Get onto the BMW warranty team and challenge that SJ aren’t treating it as a warranty claim?
If you’re going to have to pay , shop around for a specialist.
I had same car , ran it to 85k miles , injectors only issue. But I’ve heard good things about walnut blasting.
Smuler said:
Try another dealer ?
Get onto the BMW warranty team and challenge that SJ aren’t treating it as a warranty claim?
If you’re going to have to pay , shop around for a specialist.
I had same car , ran it to 85k miles , injectors only issue. But I’ve heard good things about walnut blasting.
. Get onto the BMW warranty team and challenge that SJ aren’t treating it as a warranty claim?
If you’re going to have to pay , shop around for a specialist.
I had same car , ran it to 85k miles , injectors only issue. But I’ve heard good things about walnut blasting.
Walnut blasting has to be bone every 35-40k or so I think as a matter of routine maintenance on any direct fuel injected car, youtube it, its very informative I did for my 335i
And yes these injectors too don't seem to last that long, 2 of mine were replaced before I got the car and get the odd hick up on tick over now so assuming another could be (now on 85k), but rough running could be to do with the oil breather hose, I had a clogged hose on my 330i n52 and they routinely cleaned it on my n54 when I had my walnut blasting done as I believe its hidden under the inlet manifold and that needs to come off to access it.
If we assume they have already replaced the high pressure fuel pump, id be checking the injectors. The 335i is on version/index 12 now iirc & they are a failure point as per the N53. Leave it overnight and pull the plugs in the morning, if they are leaking they will smell of petrol. The leaking causes an idle stumble on cold start.
Unfortunately, its doubtful anyone at bmw will have had any training on the n54 (its 10+ yrs old now), so as you are finding, they havent a clue...
Unfortunately, its doubtful anyone at bmw will have had any training on the n54 (its 10+ yrs old now), so as you are finding, they havent a clue...
I highly doubt it will be the coking up of the inlet system causing your issue. It will almost certainly be your injectors.
Get photo evidence of the level of coking up from the dealer and post up here or get a second opinion on the pictures. Get confirmation of all the engine fault codes still logged. If any are pointing to fuel system - then that will be nothing to do with the coking and u can ask for the faults to be rectified under warranty first.
And to add - decoking an inlet system was never part of the maintenance schedule for that engine- so it shouldn’t be considered a maintenance item by the dealers. You can ask them to show you where in the original service schedule it is written that it will need a decoke at a particular mileage or age - and if they can’t then if it requires it - it’s down to a fault and not wear and tear
Get photo evidence of the level of coking up from the dealer and post up here or get a second opinion on the pictures. Get confirmation of all the engine fault codes still logged. If any are pointing to fuel system - then that will be nothing to do with the coking and u can ask for the faults to be rectified under warranty first.
And to add - decoking an inlet system was never part of the maintenance schedule for that engine- so it shouldn’t be considered a maintenance item by the dealers. You can ask them to show you where in the original service schedule it is written that it will need a decoke at a particular mileage or age - and if they can’t then if it requires it - it’s down to a fault and not wear and tear
Got a 335i myself and the issue does seem to be pointing towards the injectors considering all the bits that have been replaced.
As for the dealers, as mentioned above the majority of them don't really have a clue with the N54 given its age. I have had issues myself (one ongoing) that was "rectified" under warranty but the problem persists.
Both my local Sytners in Essex aren't great at all. Misdiagnosis, try to reject warranty claims repeatedly and claim ridiculous things such as I put in a DCT gearbox when the only change is the shifter has been changed to a F series one.
There's a dealer in Battersea that everyone praises non stop so maybe go pay them a visit?
As for the dealers, as mentioned above the majority of them don't really have a clue with the N54 given its age. I have had issues myself (one ongoing) that was "rectified" under warranty but the problem persists.
Both my local Sytners in Essex aren't great at all. Misdiagnosis, try to reject warranty claims repeatedly and claim ridiculous things such as I put in a DCT gearbox when the only change is the shifter has been changed to a F series one.
There's a dealer in Battersea that everyone praises non stop so maybe go pay them a visit?
Thanks for all your responses. I hope everything is having a good break.
It certainly does appear to be the injectors. Part of the trouble with these places is that the "service managers" who look after the technicians seem to know less than the technicians themselves!
I was also thinking that if the system is coked it to the extent, they claim, why would it be running lean? They said that too much air is getting into the system, but wouldn't the coking up restrict the airflow? They said they also did a smoke test and everything was tight.
I'm going to demand pictures tomorrow and question them on the maintenance schedule regarding the decoking. This is the third visit in 4 weeks and it's just ridiculous now.
What is the name of the dealership in Battersea?
Thanks again
It certainly does appear to be the injectors. Part of the trouble with these places is that the "service managers" who look after the technicians seem to know less than the technicians themselves!
I was also thinking that if the system is coked it to the extent, they claim, why would it be running lean? They said that too much air is getting into the system, but wouldn't the coking up restrict the airflow? They said they also did a smoke test and everything was tight.
I'm going to demand pictures tomorrow and question them on the maintenance schedule regarding the decoking. This is the third visit in 4 weeks and it's just ridiculous now.
What is the name of the dealership in Battersea?
Thanks again
Thanks a lot for this
As an update. I have attached some images of my inlets. What do you guys think?
After a face to face visit and some gentle persuasion, they have agreed to do the walnut blasting as a "goodwill" service to me. They will be completing this tomorrow and then doing "extensive tests"
to see whether the injectors need doing. I will try to keep this updated for others who may find themselves in a similar situation.
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|https://thumbsnap.com/RGOIHjm5[/url][url]
|https://thumbsnap.com/ETY3UxZK[/url]
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|https://thumbsnap.com/Mjql7TqH[/url]
As an update. I have attached some images of my inlets. What do you guys think?
After a face to face visit and some gentle persuasion, they have agreed to do the walnut blasting as a "goodwill" service to me. They will be completing this tomorrow and then doing "extensive tests"
to see whether the injectors need doing. I will try to keep this updated for others who may find themselves in a similar situation.[url]|https://thumbsnap.com/RGOIHjm5[/url][url]|https://thumbsnap.com/ETY3UxZK[/url][url]|https://thumbsnap.com/Mjql7TqH[/url]
Sir_Dave said:
Haha. 335i in “random internet chaps knowing more than bmw dealer” shocker ... glad its all sorted, nice that they replaced all the injectors instead of one by one!! Hopefully they coded them in properly 
Hopefully! How will I tell if they're not coded in properly? Tomorrow morning will be the real test to see exactly how the car idles at cold startGassing Station | BMW General | Top of Page | What's New | My Stuff