# Life after carbon build-up



## gmrsprsav (Jan 10, 2006)

I have a 2009 ED 335d that had the SES light come on, due to carbon build up, at 56k, 4 1/2 years. I did not have an extended warranty, but BMW N/A agreed to cover the repair. The dealer has been working on this since mid September. (I don't understand the delay, when I finally get it back I'll know exactly what was done. I was told initially that they were no longer replacing the cylinder head but were having it cleaned, I think when that did not work they replaced the cylinder head, and then at least one of the injectors. It was supposed to be fixed 2 weeks ago, but then the DEF sensor went bad, and they have replaced the tank and sensor.)

Anyway, at some point I will get my car back. Does anyone have any experience of what happens next? Will this carbon up in another 30,000 - 60,000 miles? Does this repair result in other problems? Do I sell it while it is still on the lift at the dealers and finally get back to a manual transmission?


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## finnbmw (Jul 6, 2008)

gmrsprsav said:


> The dealer has been working on this since mid September.


4 months at the dealership??? :yikes:


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## DC-IT (Sep 27, 2009)

gmrsprsav said:


> I have a 2009 ED 335d that had the SES light come on, due to carbon build up, at 56k, 4 1/2 years. I did not have an extended warranty, but BMW N/A agreed to cover the repair. The dealer has been working on this since mid September. (I don't understand the delay, when I finally get it back I'll know exactly what was done. I was told initially that they were no longer replacing the cylinder head but were having it cleaned, I think when that did not work they replaced the cylinder head, and then at least one of the injectors. It was supposed to be fixed 2 weeks ago, but then the DEF sensor went bad, and they have replaced the tank and sensor.)
> 
> Anyway, at some point I will get my car back. Does anyone have any experience of what happens next? *Will this carbon up in another 30,000 - 60,000 miles?* Does this repair result in other problems? Do I sell it while it is still on the lift at the dealers and finally get back to a manual transmission?


In my case the Dealer told me to expect having to clean out carbon build-up every 50,000 miles!

I was also out of warranty so I decided not to risk it any more and traded my D in for a 2013 E350 BT!

In your case if in addition to fixing the carbon issues your DEF tank and sensor are also replaced your D should be fine for the next 50K but who knows what else may break down.

The Dealer Foreman admits that out-of-warranty BMWs are expensive to keep!

Good luck.


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## Hivolts (Nov 4, 2013)

Can we clean our own carbon out? For the Jetta's, it's not that difficult. Just remove the intake manifold and clean away. Any chance the BMW's are as easy?


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## F32Fleet (Jul 14, 2010)

Hivolts said:


> Can we clean our own carbon out? For the Jetta's, it's not that difficult. Just remove the intake manifold and clean away. Any chance the BMW's are as easy?


The build up is not inside the intake but the runners leading through the cylinder head. These runners are long, narrow, and have bends. Using a product such as Lubro-Moly Diesel Intake Cleaner at 15k mile intervals may be the ticket.


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## Hivolts (Nov 4, 2013)

What about a meth injection system for these? Many of the high powered trucks use these for power, but it keeps them clean. I know the TDI guys are using them to prevent buildup.


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## DozerDan (Dec 18, 2013)

Hivolts said:


> What about a meth injection system for these? Many of the high powered trucks use these for power, but it keeps them clean. I know the TDI guys are using them to prevent buildup.


Funny you mention that. A buddy of mine just installed a water injection set up on his truck, we were talking about it and I plan on doing the same to mine. Main gain with the water inj is lower egt's. But I wonder how it would transfer over to this application. :dunno:


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## gmrsprsav (Jan 10, 2006)

Yes, 4 months. If BMW knew how to fix this it should be 1-2 days.

And DC-IT, I think I'll follow your example.


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## Hoooper (Jun 17, 2013)

Yes, if you don't take any steps to prevent it it will come back, unless of course BMW steps up to the plate before then. Water/meth seemed to be helping some amount, but if I was starting with a new completely clean engine I would block the EGR first. Blocking the EGR is simple if you have a tool to reset codes easily.


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## GreekboyD (Jan 25, 2012)

Hoooper said:


> Yes, if you don't take any steps to prevent it it will come back, unless of course BMW steps up to the plate before then. Water/meth seemed to be helping some amount, but if I was starting with a new completely clean engine I would block the EGR first. Blocking the EGR is simple if you have a tool to reset codes easily.


How would you block the EGR and how often and what codes would it trigger?


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## Hoooper (Jun 17, 2013)

GreekboyD said:


> How would you block the EGR and how often and what codes would it trigger?


Lots of information on this thread http://www.e90post.com/forums/showthread.php?t=904968&page=9

Basically you make a blank off plate from thin steel (or another material) at the EGR. I reset the codes every time i start my car. I use the cantool from bms so its not a big deal, just wait till the ses comes on and then hold the reset for a second. Ses will come on everytime you start the car otherwise


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