[Persian Whisperjet]

Taking a page out of Maslow's book (study healthy people not just sick people) can people who have NOT had known CBU issues pipe up?

I'm at 43K miles and have had no problems and no drop-off in mileage, but given the common onset around 50K I do not place much significance in that.

Please be sure to state your model year and mileage.

Thanks in advance.

http://en.wikipedia.org/wiki/Abraham_Maslow

[Pierre Louis]

I've mentioned before that my 3 prior diesels, all direct injection with EGR etc., had no CBU associated problems (156K, 240K, and 95K miles so far) and currently the 335d is running well w/58,000 miles.

I don't use aftermarket additive, use only "top tier" fuel stations (not even the ones that say "this is not a _____ product" on the diesel pump -why would they say that if "all diesel is the same"?) I drive the same, after thinking about it, by hard downshifting on occasion which I believe "pushes" the crud out - would cause a plume of black smoke were it not for the DPF.

I find it interesting that no other variables are mentioned in most of the posts about CBU. No mention of brand of fuel, additive or not, how they drive, where they drive etc.

What we need is for someone to catalogue all of the CBU cars to get a good number. Chances are we have a percentage of all CBU on these boards. We know that BMW sold a total of about 10,000 335d's, even published the data. My guess is that many of the fans both are more likely to post about CBU and to use aftermarket additives. My other guess is that most use the cheapest diesel they can find, almost always not top-tier.

PL

[Pierre Louis]

Originally Posted by Persian Whisperjet

Taking a page out of Maslow's book (study healthy people not just sick people) can people who have NOT had known CBU issues pipe up?

I'm at 43K miles and have had no problems and no drop-off in mileage, but given the common onset around 50K I do not place much significance in that.

Please be sure to state your model year and mileage.

Thanks in advance.

http://en.wikipedia.org/wiki/Abraham_Maslow

Here is a diagram that can give you an idea of how many "studies" and "opinions" have made it to "mainstream" thinking in health care, at least in the past before the push for "evidence based medicine" came around. Notice that the tiny group that makes it into the university specialist's office would be the most studied while the general public is often not.



PL

[eurojulien]

so far no obvious signs (maybe slightly lower MPG) 56k miles

[taibanl]

55k. No confirmed CBU but notable MPG drop

[runbyu1]

76k miles. No cbu issues and the guy I bought it from before said he had no issues. I also use top tier fuel and I really like the hard downshift theory.

[g335d]

64K miles, no drop in mileage or other obvious CBU indications. 2011 335d, build date in July 2011. Since I started reading about CBU a couple of years ago I have made it a point to use only Shell or BP diesel if at all possible.

[Cliffj]

102K with no CBU issues. Rest of the info in the sig ... I occasionally add some diesel additives and have run 1qt of BG 244K through the tank, diluted per the directions on the bottle (it goes a long way).

[remlemasi]

Was about to post when just this evening I got limp mode and some codes. See other thread ("Checking for CBU").

Up until today...

72K miles (bought CPO at 44K miles)

MY2011 (10/2010 production date)

[Persian Whisperjet]

Originally Posted by remlemasi

Was about to post when just this evening I got limp mode and some codes.

<groan>

[AustinMsport]

59K no CBU

[Frediesel]

Is it more approppriate to say "No CBU codes" rather than "No CBU" unless it is confirmed- "No CBU certified"?

[floydarogers]

un-modded 2010, 90900 miles, no apparent problems.

[other_evolved]

I just rolled over 22k miles on a 2011 (albeit I've only owned it for 3 weeks) and there has been no CBU.

I did, however, throw a SES light and the nox sensors were replaced, along with the catalytic converter.

[natefank]

Just rolled 80k no CBU yet, but I drive in DS and my commute is up and over a windy hill

[335dFan]

Have a Apr 2010 production month 2011 model that I bought new in May 2012. I have 42k miles, very little of which was true city-type stop-and-go. Some long road trips, a couple of days at the track, and hammering it a lot. No indications of CBU just yet in terms of codes (likely spurious if they come) or mileage changes or performance downgrades.

[Get lit]

Production 06/2011. Just hit 50k. Haven't had any issues, codes, etc related to cbu or any other engine issues! I drive 90% highway and 10% city. I use only BP fuel. I am running a JBD @ 100%. I push the limits very often on my car, drive the hell out of it! Lol... I change oil every 5000 miles. Only issues I have had are some cosmetic stuff with the shadow line trim and both headlight washers started leaking.

[floydarogers]

Originally Posted by Frediesel

Is it more approppriate to say "No CBU codes" rather than "No CBU" unless it is confirmed- "No CBU certified"?

There are no "codes" for CBU. There are codes for miss-fires, injector adaptation values, etc. So, no, it's not more appropriate. The only way to discover if there *IS* CBU is by inspection of the intake runners.

I'm over 90K miles with no apparent symptoms of CBU (which is IMO the only thing one can say w/o inspection.)

[Sweattdogg]

73k here and no apparent symptoms other than seems my mpg is down.

[Mrchntmarine]

new from 2010, about 33k miles and top tier fuel(I think - wife's car so who knows). almost afraid to type this as I don't want to get jinxed - o2 sensor problems, catalytic converter replaced and a host of other stuff.... MPG steady so far

[EvEcentral]

2010 BMW 335d W/Sport Package (2nd owner): purchased at 70k Miles.

I purchased this car with the engine light illuminated. These engine lights correspond to CBU issues.

Vehicle History:

Build Date:03/2009
BMW purchased my BMW as a DEMO car for BMW mgt in Atalanta Georgia. (high Traffic)
this is a big cause of CBU (stop and go traffic).
Spent entire life in Atlanta until I purchased.
Now located in Huntsville Al,

Actions taken since purchased:

At 71K miles had CBU removal accomplished to intake, head, and other misc effected components. Also, required Urea tank to be replaced (known issue)
Boost Hose needed new seals, and DPF was partially clogged, EGR was toast. and turbo oil lines were starting to fail, so replaced them as well.

80K miles Deleted EGR, EGR Cooler, DPF, and SCR.
Flashed ECU with JR Stage II
Only use High Grade diesel and commercial additive for lubrication only.

81k Converted Urea Tank to Meth injection supply tank.

Dynoed at 82K

Pulled apart intake at 86K for observation and study. Found zero CBU which was to be expected since there is no EGR present

Current particulars:
43 MPG Highway Avg.
33 Mpg Hybrid Highway/City Driving
Zero Engine lights (one exception under hard load I will occasionally pop a mass airflow SEL that will reset after a couple of starts)
Engine running flawlessly with no hesitation, shutter, or stuttering on startup or operating temp running.

Remaining Issues: FRM failure (lighting Issues/Non related)

Hope this helps and thanks for starting this thread

[locolobo]

I have 57k miles now, bought the car with 33k two years ago and installed the Ecotune program. It wasn't exhibiting any noticeable problems before or since. This past summer, I had to take the intake off to replace a bad glow plug controller. So while I had it apart I inspected everything. There was some light CBU, maybe 1mm, especially around the swirl flaps. I cleaned everything thoroughly. I am running 5% biodiesel all the time and Power Service cetane boost, which should help to reduce soot and provide more complete combustion.