[diamondbacvenomx]

So I'm hoping someone can shed some light on my experience (thus-far) with the dealership...

Background: I have a 09 335i. JB4, AE Exhuast and AR DPs. I installed the JB4 awhile back when my car had 35k miles w/stock plugs. The car threw a misfire in Cylinder 5 (which I expected). I bought all new plugs and tried again. Another misfire... Swapped coils and tried again. Another misfire.

Brought it in to the dealership thinking its my injectors and my car was still under warranty at this point. This was probably late Oct. They replaced injectors 4,5,6. I asked why not all 6 and they said they only got authorization for those 3. Pretty happy anyway since I brought the car in with my exhaust mods and they said nothing about it except they liked the way it sounded.

Got the car back and installed JB4. ANOTHER MISFIRE in cylinder 5. I was leaving the country for a bit on November 20 to 22. My warranty expired the 21st. I dropped the car off the night before I left so it would be covered under warranty. So at this point I'm 95% certain its carbon buildup. But here is where the fun begins...

So between getting errands ran and packing, I had to rush to drop my car off. I cleared the codes (my mistake), removed the jb4, and dropped the car off. Well they spent 3 weeks trying to get my car to throw a fault code. The techs and even the service rep can feel the misfire but the car is too damn stubborn in stock to throw a SES. Side note...if they all can feel an issue why the hell can't they fix my issue? Is it bmw policy to not work on a car without a SES. I understand it can be 1000 things wrong so the light helps pin point what is wrong and I was the dumb dumb in clearing the fault code.

So after 3 weeks i asked to have my car back and try to throw the code myself. I went ahead an put in the jb4, threw the code and took it out. Cylinder 5 misfire fault was now stored in my ECU. Brought it back to them last Saturday. I get an email from my service rep saying that the light was not on in my dash when he brought it around to their bay. Now this got me worried...do they literally need a damn dash light to work on a car?? the fault is stored in my ECU, can't they just scan for codes in my ECU? This is where I'm confused. I've emailed my rep 3 times telling them to scan the code and he just replies they are still trying to throw a code pretty much neglecting my concerns.

This honestly makes me not want to buy another BMW if their policy is you need a light for anything to get fixed. So they have had it for a week now trying to throw a SES light...I'm about to say screw it and pay for a walnut blast myself.

[catcher22]

They had it for three weeks trying to make a light come up? Sounds kinda weird to me.

The code hasn't come back after clearing. What's the issue?

[Chefcg1]

did you try moving the coil pack to another cylinder and seeing if the misfire moved or try new plugs? I have found that my misfires have always been plug related or coil related.

[diamondbacvenomx]

Originally Posted by catcher22

They had it for three weeks trying to make a light come up? Sounds kinda weird to me.

The code hasn't come back after clearing. What's the issue?

The code won't come on in stock. I guess it isn't noticed on the stock tune although we all can feel it when we drive it hard. I use the tune to throw the code since it happens instantaneous on WOT. The tune requires more effort from the components hence why its easier to throw the code.

I did swap coils and the misfire stayed with cylinder 5. Coils have been swapped, plugs and injectors have been replaced. all that is left before it being a ECU issue is checking out the carbon buildup.

And they had the car for 3 weeks because 12 of those days I wasn't in the country. I didn't mind they had it and the service reps have been cool throughout the process, my patience is drawing to an end though.

The main thing with my ranty post is WHY do they need a dash light to work on my car? The ECU has the fault in it so why do they need to throw the code themselves before they even begin to work on it? Haven't got a straight answer from them yet.

[moralesa335]

I was an advisor for the BMW recently and my take on this situation is that they don't technically need a light on they just need the fault code logged on the ecu. The ecu stores all faults that are thrown at any time whether they show a light on or not. So if you cleared the codes there is no way for them to recover deleted faults.
Weird if they can hear the misfire that they didn't fix it. Typically their work off the idea of "duplicating the issue" for mechanical evidence. Once the mechanic finds an issue but it is not throwing a code, they can take it further to the shop foreman to get his approval to replace the part.
My experience with BMW is that persistence is the key. If you make a loud enough scene or threaten to talks to boss' boss. They'll typically do whatever you want just to shit you up.
In my days alone, I've seen a guy get a free full detail for no charge everytime and a guy who neglected to change his oil for 35k miles and got a whole new car out of it covered .....Unbelievable....

Anyway. Hope this helps. Stay on their ass and they'll buckle first. They store depends on low numbers of complaints.

[diamondbacvenomx]

Originally Posted by moralesa335

I was an advisor for the BMW recently and my take on this situation is that they don't technically need a light on they just need the fault code logged on the ecu. The ecu stores all faults that are thrown at any time whether they show a light on or not. So if you cleared the codes there is no way for them to recover deleted faults.
Weird if they can hear the misfire that they didn't fix it. Typically their work off the idea of "duplicating the issue" for mechanical evidence. Once the mechanic finds an issue but it is not throwing a code, they can take it further to the shop foreman to get his approval to replace the part.
My experience with BMW is that persistence is the key. If you make a loud enough scene or threaten to talks to boss' boss. They'll typically do whatever you want just to shit you up.
In my days alone, I've seen a guy get a free full detail for no charge everytime and a guy who neglected to change his oil for 35k miles and got a whole new car out of it covered .....Unbelievable....

Anyway. Hope this helps. Stay on their ass and they'll buckle first. They store depends on low numbers of complaints.

Perfect. Thank you.

[techwhiz]

OP, you stated you swap coils and it stayed with cylinder #5?
Did you change/inspect the plugs?
My misfires with a tune have all been plug related. Could not make it misfire with stock firmware. Dropped in the Cobb and misfire city.

Changed the plugs and misfires are gone.

[moswissa]

why dont u just goto another dealership???

[Mit_Boost]

Have you taken any data logs? It's possible you could self diagnose & at least steer them in the right direction.

[diamondbacvenomx]

I put it all new plugs already. I swapped coils and it stayed with 5. I swapped plugs even thinking it might be a DOA plug but still misfire in cylinder 5.

I can't go to a different dealership because my warranty expired and this service ticket has been open before it expired so I'm stuck with this dealer for this particular issue.

nah haven't done data logging yet. I've told them twice I think its carbon on the intake valves but they just ignore that comment and talk about needing a dash light.

[Mit_Boost]

Originally Posted by diamondbacvenomx

nah haven't done data logging yet. I've told them twice I think its carbon on the intake valves but they just ignore that comment and talk about needing a dash light.

Take some logs. It's possible you'll find a completely unrelated issue causing the problems.

[diamondbacvenomx]

Originally Posted by Mit_Boost

Take some logs. It's possible you'll find a completely unrelated issue causing the problems.

thanks, will do when I get the car back lol.