[duramax]

Okay, I dropped my car off for the second maintenance today (26K miles)and asked what he knew about CBU and how many diesels he sees. He said he sees about 2 or 3 diesels a day which I find hard to believe because I haven't seen any others in town in 2 years. Anyway, he said he has only see two with CBU issues and those were around 60K Miles. One was covered under a BMW extended warranty, the other OoP expense to the owner of about 5,500. I asked if BMW was stepping up to the plate to fix these issues and he then went on to say it is not a BMW or engine issue and that its caused by the quality of fuel. I told him I have owned five different diesels over 20 years and have never had CBU issues in the past and asked how he could say it was the fuel only. I hate it when people think you're stupid. He was not to happy after that and his tone changed and seem to want to get rid of me quickly. I would be interested to see what others are hearing from their dealers.

[Nushibo]

As mentioned in another thread. I dropped off my car for SES wednesday for injectors. Im having all injectors replaced under warranty and I slipped in the SIB while I was talking. Im confirmed to have carbon buildup BUT will not be covered under warranty as of now. I am in the process of persuading them to since a fault was found and needs to be address now before the car craps itself. The cost to me OOP would be 1100ish since they said they would meet me 50/50 for the process and the offer will stand beyond my injector repairs. Im considering it but ill also try to reduce the cost. I know the repairs are long 16-24 hours at the most. Ill see what I can dig up from BMW NA. Otherwise ill have to let it sit until another SES light comes on. Im just skeptical because the injectors failed at 51k so hopefully more solutions poor in the longer I own this platform. The EGR block i will definitely do but first i need to clean the system. PS im a 2011 D too. I also still laugh hard at the fuel quality thing. They designed a system to recycle EXHAUST gasses lol IE burnt/unburnt matter back into the intake so BMW theres a problem with that logic. Even with great fuel comes crappy exhaust material. Burning is still burning, and mixing solid materials with a binder like oil from the PVC and turbo seals = Gunky insides.

[dixy2k]

You guys need to call BMW NA and open a complaint case regarding your car. It will help in the long run, as your complaint list will grow.

The first dealer I took my car in wanted me to pay for CBU clean up, did not attempt to work together with BMW NA.

The second dealer worked closely together with BMW NA and got them to pay for the clean up. My complaints started just before the warranty expired and the first dealer kept on replacing part after part on my car chasing an illusive issue which never got fixed till I took in to the second dealer (hopefully).

[AzureHaze]

$5,500 for a CBU cleaning?! Ouch. I'm sure that included replacing the injectors and some other junk. But with the other guy that didn't have to pay a cent, was he under extended gold or CPO warranty? Some of us seeing that only the latter can save you from dropping some serious bucks once past the standard warranty.

[dixy2k]

I was quoted the same at the first dealer too. So it all depends on the dealer and your case with BMW NA, I believe.

[135i_vs_]

Some SAs, smh...

I've heard worst though...however, I let him know you are trying to bs the wrong guy. LOL

[ihbase]

When asked, my SA made it very clear that I "do not want to own the car out of warranty" because "it will be very expensive to maintain."

It does not get any more clear than that.

I suspect that BMW has no incentive to assist with the CBU issue because they would prefer to sell you a new car and push the CBU costs onto the secondary market in the form of accelerated depreciation.


-Michael

[skychismo]

My SA told me my CBU was caused by BMWs EGR design. He said it will keep happening on this car. He also told me the new diesels have a redesigned EGR which helps solve the CBU problem.

[DieselRacer]

Originally Posted by skychismo

My SA told me my CBU was caused by BMWs EGR design. He said it will keep happening on this car. He also told me the new diesels have a redesigned EGR which helps solve the CBU problem.

high pressure and low pressure egr valve, that's why when it is cleaned time to block egr...

[Yozh]

Originally Posted by duramax

...he then went on to say it is not a BMW or engine issue and that its caused by the quality of fuel.

It's interesting that BMW goes on for 10 pages talking about diesel fuel in their Technical Training manual. They specifically refer to ULSD that is available in the US since 2007, etc. They specifically mention now E90/X5d were adapted to different fuel in North America by changing/adapting a whole list of components and what other innovations (eg.: SCR) are in for these two cars with North American introduction. They surely must have considered fuel quality in this side of the Atlantic.

However, the manual is also contradictory as far as fuel quality references are concerned. At least to me:

"...Cetane ratings are in a range of 0 to 100. 100 is
an indicator of pure Cetane (n-hexadecane), or the most combustible.
Most commercially available diesel fuel has a cetane rating
of about 45. A rating of 40 is usually considered to be the
absolute minimum rating for today’s passenger vehicles. Newer
BMW vehicles will require a Cetane rating of 51. Always check the
owner’s manual to see the minimum fuel requirements and the recommended
cetane number. A higher cetane rating also contributes
to better starting especially in cold weather. When possible,
it is always better to use fuel with a higher cetane rating. Also,
a higher cetane number equates to a reduction in NOX and particulate
matter emissions..."

Newer BMWs will require a 51 cetane, but 45 cetane is commercially available. Duh.

[Yozh]

Oh, and one mechanic (shop foreman, not a dumbass SA) at a BMW dealer told me that every one of the 335d he sees are plagued with carbon. I did not inquire about a warranty coverage as I do not have one and will deal with this mess on my own (EGR already blocked, the rest to come).

[duramax]

Interesting comments. I have another year before I have to buy the extended warranty. I guess I will start driving it more as opposed to my other car and make the decision at that time depending on how things go and block the egr at that point. I usually keep my cars for 10+ years, so even with the extended warranty I will have to do something at some point. I just wish it was easy as my truck by pulling a plug/connector.

[Nushibo]

Originally Posted by duramax

Interesting comments. I have another year before I have to buy the extended warranty. I guess I will start driving it more as opposed to my other car and make the decision at that time depending on how things go and block the egr at that point. I usually keep my cars for 10+ years, so even with the extended warranty I will have to do something at some point. I just wish it was easy as my truck by pulling a plug/connector.

Consider that warranty may not cover CBU. As in my case im trying to work with BMW NA to at least have it covered if it occurs down the road after my injector failure repair. I plan to drive the car until I get it cleaned then block the EGR once a tuner close by like Renntech can code it out.

[stevers314]

Originally Posted by Yozh

It's interesting that BMW goes on for 10 pages talking about diesel fuel in their Technical Training manual. They specifically refer to ULSD that is available in the US since 2007, etc. They specifically mention now E90/X5d were adapted to different fuel in North America by changing/adapting a whole list of components and what other innovations (eg.: SCR) are in for these two cars with North American introduction. They surely must have considered fuel quality in this side of the Atlantic.

However, the manual is also contradictory as far as fuel quality references are concerned. At least to me:

"...Cetane ratings are in a range of 0 to 100. 100 is
an indicator of pure Cetane (n-hexadecane), or the most combustible.
Most commercially available diesel fuel has a cetane rating
of about 45. A rating of 40 is usually considered to be the
absolute minimum rating for today’s passenger vehicles. Newer
BMW vehicles will require a Cetane rating of 51. Always check the
owner’s manual to see the minimum fuel requirements and the recommended
cetane number. A higher cetane rating also contributes
to better starting especially in cold weather. When possible,
it is always better to use fuel with a higher cetane rating. Also,
a higher cetane number equates to a reduction in NOX and particulate
matter emissions..."

Newer BMWs will require a 51 cetane, but 45 cetane is commercially available. Duh.

Funny how we are verboten from using cetane booster additives.

[Frediesel]

Originally Posted by skychismo

My SA told me my CBU was caused by BMWs EGR design. He said it will keep happening on this car. He also told me the new diesels have a redesigned EGR which helps solve the CBU problem.

Would the redesigned egr be an option for the 335d?

[modobrew]

Welp, my D threw the cylinder 2 code again, 2nd time in the last month. First time they replaced all 6 injectors. My SA said based on their knowledge of the D's with the recurring issue, they believe the intake cleaning will be performed this time. I drop it off next week. Hopefully the intake cleaning will be performed. I also made sure to ask if this cleaning is cover under my warranty; 6 yr/100k Gold Package for those interested. I'll let you guys know what I find out next week.

[grzes]

well from what I know they will not touch CBU unless PUMA case is open due to some engine issue that they can not resolve. That is what happened in my case and then they did everything under my 6 yr / 100 k warranty. My engine was going into the limp mode as soon as I accelerated harder and they had no clue why so PUMA was involved and it was them telling the dealer to clean the CBU.

[Nushibo]

Originally Posted by grzes

well from what I know they will not touch CBU unless PUMA case is open due to some engine issue that they can not resolve. That is what happened in my case and then they did everything under my 6 yr / 100 k warranty. My engine was going into the limp mode as soon as I accelerated harder and they had no clue why so PUMA was involved and it was them telling the dealer to clean the CBU.

Yea I figured. So ill just drive my car with the new injectors until something happens.

[modobrew]

Originally Posted by Nushibo

Yea I figured. So ill just drive my car with the new injectors until something happens.

Thats what i did. took less than a month for something else to happen. Light came on when i stepped on it merging into traffic. not sure why that would cause the SES light to come on and throw a cylinder 2 code.

[grzes]

Originally Posted by modobrew

Thats what i did. took less than a month for something else to happen. Light came on when i stepped on it merging into traffic. not sure why that would cause the SES light to come on and throw a cylinder 2 code.

there is many things that happen to our engines that even dealers have no clue why lol despite all those error codes lol. CBU was a start of my problems lol, after CBU more came on line injector, air mass flow sensor few more sensors (don't remember them all) and at the end they had to replace DDE unit and that solved all the problems . I have asked the dealer why it was so hard for them to pin the problem despite all the error codes that are suppose to help them and he had no answer lol

[skychismo]

Originally Posted by Frediesel

Would the redesigned egr be an option for the 335d?

It would be interesting to see if someone could retrofit one to work. They're entirely different engines so it might be tricky.

[Frediesel]

I was thinking the egr from the 535d