# Carbon Build Up a 335d issue?



## arplayer2k (Nov 2, 2004)

DaveN007 said:


> I talked to my SA today. He just returned from some kind of BMW conference.
> 
> He says that the walnut blasting attachments they are getting will clean the valves...BUT NOT THE INTAKES...which need to be replaced or sent away for cleaning. So intake build-up will continue to be a problem.
> 
> ...


I just purchased a 335d CPO. I have been told that the Carbon Buildup issue is only covered in certain cases, not broadly. You probably know more, can you clarify this?

Thank you!


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## DaveN007 (Oct 4, 2013)

arplayer2k said:


> I just purchased a 335d CPO. I have been told that the Carbon Buildup issue is only covered in certain cases, not broadly. You probably know more, can you clarify this?
> 
> Thank you!


I can only relay what my SA told me.

If carbon build up is determined to be the root cause of a problem with the car, the intake cleaning (or replacement) and walnut blasting would be covered by the factory warranty or the CPO warranty.

This just means that *I* have a commitment from a guy who might quit tomorrow. 

I doesn't mean much else.


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## Orygun (Dec 8, 2013)

BMW's SIB 11 03 14 covers the CBU cleaning and explicitly states it's covered by the BMW factory and CPO warranties. 

Quote from the SIB: "WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle/SAV Limited Warranty or the BMW Certified Pre-Owned Program."

I don't think anybody on here has had a verified case of CBU that wasn't eventually accompanied by the SES light and associated fault codes that the SIB requires. Plenty of people worrying about it, or thinking they might have it, but too much worrying makes you paranoid and you start seeing aliens in your closet. 

I was on the Ford Superduty forums in 2000 when "cackle" was the big issue and "every Ford 7.3L Powerstroke was doomed to premature failure" by the doomsayers. 14 years later mine, and virtually every other 7.3L powerstroke built that year and since, are still on the road and running strong.

I was on the VW TDI forums in 2010 when all the doomsayers were condemning every Bluetec TDI to certain premature death from HPFP failures. 120K accumulated miles later (for me) with no issues, and every person I personally know with one is still on the road. 

Here, now, it's CBU. Every US 335d is doomed to premature failure from CBU. Will mine get it? Maybe, probably, I don't know. If I do up until 100K I'm covered by the BMW warranties. After that, maybe I'll do the EGR delete/catch can/ meth route, maybe I won't. There's a known fix out there if I get it, and even if it's on my dime it's more reasonable than the $14K horror stories from the TDI forum's HPFP failures. 

Drive more, worry less. :bigpimp:


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## arplayer2k (Nov 2, 2004)

Orygun said:


> BMW's SIB 11 03 14 covers the CBU cleaning and explicitly states it's covered by the BMW factory and CPO warranties.
> 
> Quote from the SIB: "WARRANTY INFORMATION
> Covered under the terms of the BMW New Vehicle/SAV Limited Warranty or the BMW Certified Pre-Owned Program."
> ...


Well said. Thanks.


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## sirbikes (Aug 17, 2012)

Ugh ... just got my first major code -- an engine malfunction light came on tonight, the big icon on the dash. Here's what I was doing. Every so often I give it the boot. Well, on my way home, there's this steep on ramp onto the highway about 1/4 mile long or so where I like to floor it and put considerable load on the engine. There were a couple of cars in front, so I drove really slowly (no one behind me) until they were near the top, then I floored it. Got to about 85 mph or so and the revs were right near 5000rpm, then the light came on. Slowed down to about 70 and cruised home (about 12 miles). Got home, went to the pool. Drank beer. Maybe it will go away. Else off to my mechanic on Monday.


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## Pierre Louis (Oct 23, 2011)

sirbikes said:


> Ugh ... just got my first major code -- an engine malfunction light came on tonight, the big icon on the dash. Here's what I was doing. Every so often I give it the boot. Well, on my way home, there's this steep on ramp onto the highway about 1/4 mile long or so where I like to floor it and put considerable load on the engine. There were a couple of cars in front, so I drove really slowly (no one behind me) until they were near the top, then I floored it. Got to about 85 mph or so and the revs were right near 5000rpm, then the light came on. Slowed down to about 70 and cruised home (about 12 miles). Got home, went to the pool. Drank beer. Maybe it will go away. Else off to my mechanic on Monday.


My theory for why I needed NOx sensors and 2 new catalytic converters is that I had not been doing that maneuver, flooring it briskly so that it downshifts and powers on, until the time right before this happened. The theory is that too much CBU came through and lodged itself in the converters overloading and "frying" them. Don't know if the additive I used contributed: a bottle of Sta-Bil for diesels that Walmart had on red dot sale, in the proper dosage of course.

PL


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## floydarogers (Oct 11, 2010)

Orygun said:


> ...
> Here, now, it's CBU. Every US 335d is doomed to premature failure from CBU. Will mine get it? Maybe, probably, I don't know. If I do up until 100K I'm covered by the BMW warranties. After that, maybe I'll do the EGR delete/catch can/ meth route, maybe I won't. There's a known fix out there if I get it, and even if it's on my dime it's more reasonable than the $14K horror stories from the TDI forum's HPFP failures.
> 
> Drive more, worry less. :bigpimp:


++


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## sirbikes (Aug 17, 2012)

Started car this morning and light is gone. I don't know if it will come back, but I don't want to worry that something bad is going to happen if I push the car. I mean, what's the point of having the ultimate driving machine, then? Might as well drive a Subaru Outback. I'll probably take it in on Mon to have it checked out. Incidentally, this is the first time I filled up with bp diesel and no additive.


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## Pierre Louis (Oct 23, 2011)

sirbikes said:


> Started car this morning and light is gone. I don't know if it will come back, but I don't want to worry that something bad is going to happen if I push the car. I mean, what's the point of having the ultimate driving machine, then? Might as well drive a Subaru Outback. I'll probably take it in on Mon to have it checked out. Incidentally, this is the first time I filled up with bp diesel and no additive.


Sorry to hear about the SES light. Its very disappointing I'm sure.

Let us know what they find. Good luck.

PL


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## Pierre Louis (Oct 23, 2011)

sirbikes said:


> Ugh ... just got my first major code -- an engine malfunction light came on tonight, the big icon on the dash. Here's what I was doing. Every so often I give it the boot. Well, on my way home, there's this steep on ramp onto the highway about 1/4 mile long or so where I like to floor it and put considerable load on the engine. There were a couple of cars in front, so I drove really slowly (no one behind me) until they were near the top, then I floored it. Got to about 85 mph or so and the revs were right near 5000rpm, then the light came on. Slowed down to about 70 and cruised home (about 12 miles). Got home, went to the pool. Drank beer. Maybe it will go away. Else off to my mechanic on Monday.


:beerchug: Beer is a good additive....


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## sirbikes (Aug 17, 2012)

I got around to hooking up my code reader. Here is the generic code info:

P02CB
Turbocharger / 
Supercharger B
Underboost
Condition
PENDING


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## sirbikes (Aug 17, 2012)

My mechanic could not find anything wrong with my car (no leaks, valve issues, excessive carbon buildup, etc). His theory is that maybe the EGR valve closed a bit too slowly given the fuel / boost request but still closed within spec so no egr code got thrown. Maybe some buildup in the egr. Could also be my tune but I haven't had this issue when flooring it before, and I have it set halfway, currently at 5 (I sometimes get injector qty codes if I go beyond 6 out of a 0 to 9 pot).


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## Hbones (Aug 20, 2014)

sirbikes said:


> I got around to hooking up my code reader. Here is the generic code info:
> 
> P02CB
> Turbocharger /
> ...


I've experienced the same power loss and "Engine Malfunction Reduced Power" message on my 2010 X5d. I pulled the same P02CB code as well as code P2621 which is "Throttle Position Output Circuit Low". I've reset the codes a few times but they seem to keep coming back. Anyone know if these codes are related? A number of things I've been reading seem to point to the Throttle Position Sensor and mention testing the voltage to and from the TPS.


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## sirbikes (Aug 17, 2012)

Well, my engine malfunction light came back on and with a vengeance. This time I was 200 miles from home, and the car went into limp mode. I don't know if you've ever driven a heavy diesel car with no turbos, but let me tell you, it's not a good day. I limped 200 miles back home like a slug. 

But I made it, and got it to my mechanic. All signs point to stuck egr valve. So I am having it removed and probably replaced. Thought about removing it and cleaning it myself, but don't have the time and I need the car for a weekend trip. Besides, there seems to be a heavy buildup on the egr, which means there is probably cbu in my intake and on my injectors. I am amazed because I had induction service performed not 20k miles ago. The buildup happens fast. My service advisor told me that they are seeing more and more cars with cbu. So now this is starting to happen to the X5s. Mine is at 76k miles. I started to see a drop in mpg and shorter regen cycles. I thought it was because it was very hot and humid here and I'm using the a/c, but maybe not. Maybe it's the cheap fuel I use. I've been using additive and giving it a good boot once a week, but I'm not sure any of that matters. Maybe it's something else. 

Well, I gotta determine the extent of the buildup and risk to an injector going. What I've got to figure out is, if it's going to cost me more than a certain amount for repairs, or some annual amount greater than $X, than I may trade the thing in for a 328d wagon. With the much better mpg, and the amount of driving I do, ~20k per year, I may come out ahead.


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## sirbikes (Aug 17, 2012)

[Edit: Duplicate post]


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## soroco1136 (Dec 28, 2012)

I had to have the top half of my engine replaced around 68k miles ( for carbon build up). I had a bitch fest with BMW and they covered the bill with a$1000.00 deductible. My car was in the shop for almost 4 months and the repair was alost $16k. I put 68k on my car in 26 months so my 2010 335d was one of the first to have this issue. ( car has only been serviced at a BMW service center).. I had to have the EGR cooler replaced at 105k for around $1200.00. I love my car but it does require some high priced fixes. I am just crossing my fingers at this point.
Only spend the money if you want to keep your car for a long time.


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## sirbikes (Aug 17, 2012)

Update: The new egr cleared all codes except for one. I'll post a pic of the fouled up one when I pick up my car. The boost pressure sensor was all fouled up with carbon and could not be cleaned to where it would work (the remaining code), so it needs to be replaced. The intake is not bad, probably some buildup on the rings, but he'll add a bottle of BG MOA when he does the oil change, and some BG 244 in the fuel tank every six months. Also, no more off brand diesel for me. And we'll see how it looks in another year, or 20k miles.


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## Pierre Louis (Oct 23, 2011)

Here is something that is available to remove/replace the EGR, FYI

http://www.ebay.com/itm/181501147070?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT


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## sirbikes (Aug 17, 2012)

My only concern with these egr deletes is that they are all made in Europe and they may not be compatible with the US spec diesels. Otherwise this part is less expensive than what I just paid for my replacement egr.


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## GreekboyD (Jan 25, 2012)

sirbikes said:


> My only concern with these egr deletes is that they are all made in Europe and they may not be compatible with the US spec diesels. Otherwise this part is less expensive than what I just paid for my replacement egr.


A guy near me has done dozens of them in Canada and some US guys have driven to his shop too or sent their DDEs to him.


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## need4speed (May 26, 2006)

Orygun said:


> SIB 110314 (attached for your viewing pleasure) states that CBU cleaning is covered by the 4/50K factory warranty and the 6/100K CPO warranty if accompanied by an SES light and possible fault codes. W/out the CPO there is no written coverage past the 4/50K factory warranty. Whether BMWNA is covering it under goodwill after the warranty expires, I have no idea, but it's *worth pursuing*. There's just nothing in writing covering it.
> 
> FWIW,
> Joe


May as well, something is clearly an issue with the carbon build up. N4S


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## Santorini Blue (Apr 7, 2014)

Next door neighbor bought a used 335d about a month ago. Lexus hybrid now sits in his driveway. Resale on this model is down the tubes with all the V8s that need a $5000 service every 3 years. If BMW loses the battle with MB and Audi, it's because they turned their back on their engines. Engines are their heritage.


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## gator_babito (Jun 25, 2010)

*CBU on 335D*

I called the BMWNA folks and had to convince them that they do the CBU servicing free of charge, it took some convincing but they agreed to do it. I am now waiting for the past 2 weeks to be scheduled with a loaner as this takes a few days at the dealership in my town, Gainesville, Florida. I am now scheduled to have it done by middle of next week. Will let you all know how it goes....XX

gb


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## oictaylor (Oct 5, 2016)

*335D carbon problem*

Still no recall regarding the 335D carbon build up??
This will be the last BMW if this is how they handle known problems


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## KeithS (Dec 30, 2001)

oictaylor said:


> Still no recall regarding the 335D carbon build up??
> This will be the last BMW if this is how they handle known problems


This is not unique to the Diesel, it just happens more quickly. Every direct injection engine, including gasoline is subject to carbon built up. As this has become the standard design, it is happening to more and more cars, not just BMW. But very it is true it happens more quickly and intensely in the Diesel.

They have a handle on the cleaning process, you just need to consider it one of the major maintenance items. Have you priced a tune-up for a newer gasoline BMW? In a sense you are trading this cost for that of CBU cleaning in the diesel.


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## oictaylor (Oct 5, 2016)

It is ridiculous and a poor design. 
Had anyone proposed a class action if BMW won't take care of their customers. 
They're looking one member of their cult following....the 2010 radio was bad enough but everyone knows the carbon build up is not even within reason.


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## magbarn (Jan 28, 2003)

I love everything about my car except this. Still haven't sold her, but unfortunately my finances are not as good as they were in 2010 and I'm seriously considering trading her in for something more reliable like a gutless E90 328i! The cost of CBU is bad enough, but it's seriously compounded with the extremely expensive injectors that tend to pop with the CBU along with the cursed DEF system. This car is a keeper if you're in a non-CARB state with no diesel inspections as you can do an ABC delete, but this car is way too expensive post warranty period here in CA.


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## gator_babito (Jun 25, 2010)

*BMW 335d CBU*



oictaylor said:


> Still no recall regarding the 335D carbon build up??
> This will be the last BMW if this is how they handle known problems


Well, I had the service done to clean up the CBU in March 2015, and that put the SES light to sleep for about 4 months and then it came back again. This time, I took it back to the dealership and told them to fix it as they told me it was some other problem involving the starter and I paid for it this time. It worked fine until in August 2016, i had the SES light come on again. This time, I took it to a local German car specialist, who gave me a long laundry list to fix including another starter glow plug problem, transmission pipe replacement etc. etc., cost=$2,300!! which I thought is maintenance costs at 53,000 miles. SO, I shelled out the amount and got everything fixed. It ran fine until yesterday and the SES light is back up again. Sick of this really. Its a pity, the car drives like a gem though, really enjoy driving it but for these nagging SES light issues...

Much appreciate suggestions and comments...


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## Pitiku' (Nov 30, 2016)

*Disappointed!*

Okay guys...after years of reading on the forum is time to provide a full update at 104,000 miles.

Bought the car new as present for my wife, while living in Atlanta (warm climate). Picked the car up in Germany and had a great time driving on the Autobahn. Loved the car then, and love the car now. It is one of the most satisfying drives you can possibly take in a car. It just makes you smile from time to time. 
At 3K miles we experienced the first issue...a loose belt that created the loudest noise you can imagine, at start-up for the most part. After 3 trips to the dealer and more than 1 month in service, they decided it was a 5 series belt installed on a 3 series car. 
At 15K miles we had this annoying rattle coming from the back seat....a loose shade that service department could not pick-up on and had to repair myself ($3 later and tube of black caulk to match factory noise was gone).
At 46K miles we had our first encounter with the SES light. 
Symptoms: A little shake at idle (misfire), significant loss of power, reduced fuel economy (hard to get to 32mpg on highway at 75-80 Mph)
1+ month at the dealer, 2 visits from the factory engineer, Spartanburg factory, manifold replacements, endless injectors, and many tests they finally agreed and dived into the engine to check for CBU. It was a shock to me to see an engine with such low miles having this kind of silt. When my advisor sent me the pictures showing the inside of the engine I was baffled. The guy literally had a hand full of black sand. So, they cleaned the engine, replaced the catalytic converter, NOX sensors and put the car back on the road. 
At 50K miles replaced 2 more injectors.
Bought Extended Warranty!!!!!!!
At 99K+ SES light came back on. CBU again!!!! Well, at this point you are starting to do the math and prepare yourself for a $2500+ bill every 50K or so and just live with it. So, the engine got cleaned, a few injectors replaced and back on the road we go. 
Until last week....104K+ light comes on. Took the car in and over the break I got a call. Catalytic converter failed. $2620 to repair. 
Remember? The first time they did the repair they replace all parts...why not at 99K? I know why....because the computer does not indicate so. Does a computer tell you to replace a water pump when you do the timing belt? No for crying out loud. Is just COMMON SENSE. But not in today age when you can screw the poor guy for some fine $'s.

What now? Is this even right? We all know BMW has a major design flaw where basically they restrict the engine from breathing to meet the emissions. We also know that a performance engine with the proper servicing should last and perform a long time...btw I change my oil every 7500 miles, basically at half interval and only at the dealer so they can have the records (because I do!!!).

Is there something that can be done? Do any of you know of a class action law suit for this issue? (Never sued anyone for the record). But this is getting frustrating due to the amount of dollars spent and rude customer service from BMW HQ.

Again, love the car . Very sad and disappointed!

Comments welcomed.


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## rbreding (Sep 6, 2016)

Was the CBU issue solved on the 328d or has noone crossed that threshold yet to see if it needs cleaning at some point ?


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## floydarogers (Oct 11, 2010)

rbreding said:


> Was the CBU issue solved on the 328d or has noone crossed that threshold yet to see if it needs cleaning at some point ?


Maybe both; haven't seen any reports. My wife has only 44K on hers, no problems.


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## Pitiku' (Nov 30, 2016)

*328d*

I haven't heard of any issues with 328d....grew up in Europe and BMW has this engine over there with no issues what some ever. I think you will be okay.


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## floydarogers (Oct 11, 2010)

Pitiku' said:


> I haven't heard of any issues with 328d....grew up in Europe and BMW has this engine over there with no issues what some ever. I think you will be okay.


It may have been there for a while, but the emissions systems are new since 2009. You can't compare older BMW diesel engines to recent ones that have the full array of emissions systems. Note that there were just above 10,000 E90 335d sold (and additional x5d) from 2009-11 with these systems; essentially we owners were being a beta test for those systems. BMW learned quite a bit from the failures on these cars, and we hope that the 328d are better because of that experience, but there is no guarantee.


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## KeithS (Dec 30, 2001)

Pitiku' said:


> Okay guys...after years of reading on the forum is time to provide a full update at 104,000 miles.
> 
> ....Again, love the car . Very sad and disappointed!
> 
> Comments welcomed.


This is hard to read as I am nearing the 100K point. At 86K miles our car has been pretty reliable except all the recalls, the common A/C belt, one CBU cleaning (as we all know very expected) and one NOx sensor. I still have all the original injectors, DPF and catalytic converter. Needing multiple sets of injectors is very unusual (most times they are not the problem when changed) and needing a new catalytic, especially 2 of them, I've never heard of on these boards. My inclination is either there is something else going on to cause catalytic failure, or it's not actually bad. Just like they were constantly changing injectors when all that was needed were the zero mass adaptations reset.

You may be able to get BMW to goodwill the catalytic as an extension of the CBU process that was under warranty. But as indicated, something is not following the typical pattern here.


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## gator_babito (Jun 25, 2010)

Wow, 104K miles, that’s quite a bit of mileage but i guess not on a diesel engine. In any case, I have had these CBU problems causing the SES light go on quite a few times starting even at very low mileage on my 2010 335D. I kept taking it to the dealership and finally after 5 years warranty time passed, I had the SES light come on and in 2015 summer. The dealership told me they had to clean the carbon deposits by taking out the flange and scraping it etc. with some special liquid and that it would cost me $2.5K. I called BMW North America and convinced them to give it to me free of charge as it was a recurring problem that started before the warranty expired. Somehow, after a couple of days, they called me back and said OK. So, I got that fixed and again within 6 months of inner city driving, it came back on. This time i took it to a mechanic who is known to work on BMWs and he charged me $265 and it was a replacement of the injector and not CBU. But gave me a long laundry list of repairs that cost me $2600 and I got it done because he said my car had 53K miles on it and these are things to get done at 60K miles anyways. I was surprised that a car that costed me $48K brand new should have so many problems at 52K miles. This was in August 2016. I still only have 55K miles on this puppy and am keeping my fingers crossed. However, I am really tempted to sell it and get another car that doesn’t have so many issues. The car drives wonderfully though and its a pity that BMW did not get it right in terms of their emission controls. I agree with the comments posted earlier that BMW was beta-testing all those who purchased this model between 2009-11. I do agree that a small court claims law suite ought to be filed and if several people do it, BMW will have to recall all these models and do something for the customers. BMW has a reputation for producing really good cars and this is definitely out of line for them to put out lemons.


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## Pierre Louis (Oct 23, 2011)

It amazes me how few posts are technically and scientifically oriented to discuss all possible factors, especially the idea that there are many 335d's (only a handful post their CBU problems on here out of over 10,000) that have no CBU related problems for over 100,000 miles.

The first intuitive thought in my mind is quality of fuel, quality of crankcase oil, update to DDE, etc. are the only factors that have a potential differentiating effect, assuming of course uniform manufacturing quality control.

PL


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## floydarogers (Oct 11, 2010)

IIRC, Pierre and I are two (out of quite a few, actually) that have never had indications of CBU. I'm now at 114K and I think Pierre is similar mileage.

Of course, I'm currently dealing with a 4ABC - active tank level sensor... Stupid DEF tanks.:thumbdwn:


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## MaxOshkosh (Jan 29, 2013)

*Can anyone comment on BioDiesel content?*

My manual indicates using biodiesel only up to B7. I've asked various stations around the country and some know but most have no clue and most of the time there are no pump markings as to the content. I understand some states, including Minnesota and Illinois, have legislation requiring a biodiesel content above B7. Is it possible that the problem 335d owners (including me) have been unwittingly using diesel with too much bio content? Both Mercedes and BMW have stated that too much biodiesel will cause severe problems.
Anyone with experience?


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## Pierre Louis (Oct 23, 2011)

floydarogers said:


> IIRC, Pierre and I are two (out of quite a few, actually) that have never had indications of CBU. I'm now at 114K and I think Pierre is similar mileage.
> 
> Of course, I'm currently dealing with a 4ABC - active tank level sensor... Stupid DEF tanks.:thumbdwn:


Yes, I'm now at 97,000 miles with no signs of CBU problems (no change in power or fuel economy, runs great) and have the DEF tank temperature probe CEL, working toward a solution.....

PL


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## Hoooper (Jun 17, 2013)

Pitiku' said:


> Took the car in and over the break I got a call. Catalytic converter failed. $2620 to repair.
> Remember? The first time they did the repair they replace all parts...why not at 99K? I know why....because the computer does not indicate so. Does a computer tell you to replace a water pump when you do the timing belt? No for crying out loud. Is just COMMON SENSE. But not in today age when you can screw the poor guy for some fine $'s.


Catalytic converter replacement has nothing to do with CBU, they are not normally fixed at the same time. It would be more like replacing your glow plugs since youre already under the hood replacing the air filter. You just had unlucky timing with the two.


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## Pitiku' (Nov 30, 2016)

Is SHELL still one of the best diesel around?

pitiku'


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## Pierre Louis (Oct 23, 2011)

Pitiku' said:


> Is SHELL still one of the best diesel around?
> 
> pitiku'


Yes. Shell has shown a marketing commitment to diesel, has its own pipeline, now has BMW using its products, and has had some of the best fuel over the years in my experience. I've spoken to two Shell engineers that had much to do with additive tech and was impressed.

The other good stuff seems to be from Chevron, with a similar record of diesel-oriented marketing and quality. I'm certain most "top tier" fuel companies have good diesel also, and would not skimp on quality as some "off brands" have been known to do.

With resources devoted to national and worldwide marketing, it would be strange for these companies to skimp on quality control and product. I've had good luck so far with no noticeable CBU in any of my direct injection diesel cars - 4 of them with at least 97,000 miles and counting. Two, my old E320 CDI and 2002 TDI kept getting better with mileage.

PL


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## montr (Oct 7, 2006)

Pierre Louis said:


> It amazes me how few posts are technically and scientifically oriented to discuss all possible factors, especially the idea that there are many 335d's (only a handful post their CBU problems on here out of over 10,000) that have no CBU related problems for over 100,000 miles.
> 
> The first intuitive thought in my mind is quality of fuel, quality of crankcase oil, update to DDE, etc. are the only factors that have a potential differentiating effect, assuming of course uniform manufacturing quality control.
> 
> PL


I think that you have a 2011 model. My 2010 was built in September 2009, pick at the Performance center in SC in November 2009.

I drove the car 35K miles with the old EGR valve design and software. There was a recall, campaign SIB 18 05 12. They changed the EGR valve, emission components and reprogrammed the DDE. This recall was to reduce the CBU problem at that time. If there are no CBU problems, why there was a recall. Is it to fix an imaginary problem?

BTW, not everyone with CBU or reliability problems will post on this forum or other forums.


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## PDXBMW335d (Dec 27, 2016)

I have a 2011 335d with 61k miles. I bought it a year ago with 50k miles, since then I have replaced 2 Knox sensors, diesel particulate filter and now just had to bring it in for CBU. I don't have a BMW warranty and am bummed with how expensive this fix is. Everything I've read implies that there will be a trail of problems following this. I am tempted to sell but LOVE THIS CAR! Thoughts?


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## floydarogers (Oct 11, 2010)

PDXBMW335d said:


> I have a 2011 335d with 61k miles. I bought it a year ago with 50k miles, since then I have replaced 2 Knox sensors, diesel particulate filter and now just had to bring it in for CBU. I don't have a BMW warranty and am bummed with how expensive this fix is. Everything I've read implies that there will be a trail of problems following this. I am tempted to sell but LOVE THIS CAR! Thoughts?


I feel your pain and joy. Just had my DEF tank replaced to fix the fricking 4BAC level sensor fault. But after just 150 miles, the CEL is back on with 4D16/4D17 (DeNOx efficiency). Probably a transient fault...


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## Nadir Point (Dec 6, 2013)

Always the overachievers, BMW's 335D emissions system is designed for high rate CBU build-up and maximizing cluster SES wattage dissipation.


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## soroco1136 (Dec 28, 2012)

PDXBMW335d said:


> I have a 2011 335d with 61k miles. I bought it a year ago with 50k miles, since then I have replaced 2 Knox sensors, diesel particulate filter and now just had to bring it in for CBU. I don't have a BMW warranty and am bummed with how expensive this fix is. Everything I've read implies that there will be a trail of problems following this. I am tempted to sell but LOVE THIS CAR! Thoughts?


I had the same issue fixed around 55k miles but relatively few repairs since then. I now have 137k. I am currently replacing the SCR tank and metering valve. About $3200.00. Great car but it will cost u to keep it if you drive higher miles. I wouldn't recommend a diesel to anyone. All of the problems have been the fuel delivery systems. Good luck.


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## soroco1136 (Dec 28, 2012)

soroco1136 said:


> I had the same issue fixed around 55k miles but relatively few repairs since then. I now have 137k. I am currently replacing the SCR tank and metering valve. About $3200.00. Great car but it will cost u to keep it if you drive higher miles. I wouldn't recommend a diesel to anyone. All of the problems have been the fuel delivery systems. Good luck.


FYI. I am the only owner of this vehicle and all work had been done by BMW


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## DnA Diesel (Jul 31, 2010)

Pierre Louis said:


> It amazes me how few posts are technically and scientifically oriented to discuss all possible factors, especially the idea that there are many 335d's (only a handful post their CBU problems on here out of over 10,000) that have no CBU related problems for over 100,000 miles.
> 
> The first intuitive thought in my mind is quality of fuel, quality of crankcase oil, update to DDE, etc. are the only factors that have a potential differentiating effect, assuming of course uniform manufacturing quality control.
> 
> PL


Pierre, agree that fuel, oil and DDE s/w are the major controllable factors, along with driving usage that may not be as controllable.

I'm at 190,000km/117,000mi with no hint of CBU. Fuel: Shell VPower or other brand-name premium diesel, always LL04-rated oil, had SIB 18 05 12 done years ago and my first 140,000km/85,000mi were long-range (2-3hr) commuting.

I do think I was fortunate that my copy of BMW's DEF beta-test has worked so well, but I think high-quality fuel and driving profile has helped me avoid CBU to date....keeping fingers crossed, but it seems to have settled into a long-term groove to run and run and run...perhaps I'm statistically fortunate?

Regards
DnA


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