[dzlmoose]

With all this talk about the Carbon build up issue, I thought it might useful to gather some data. Whether or not you have experienced this issue or not please contribute. I think these are some of the key factors which are relevant to this issue.

Please state:

Model year
335d or X5d
Mileage
Mpg (Please use the figure found in your BMW)
Avg speed (Please use the figure found in your BMW)
Brand of fuel (cetane rating if known)
On a scale of 1 to 5 how hard do you drive? (1 meaning: I baby my car, 5 meaning: I drive like I am being chased by Cops.)
Highway/City Mix

Carbon build up issue yes or no?

Additional Info:

[dzlmoose]

2011
335d
22158
23.7mpg
26.2
Petro Canada
3.5
70/30

Carbon build up issue yes or no?
No

Additional Info:

I bought this car used and it had 16,200 miles on it.

[Julesandtrish]

2010
335d
66,100
33.6
46
Shell
3.8
65/35
NO to carbon build up.

Additional: bought new & lovin it!

[Merv]

2011
335d
29890
34.5 avg MPG
39.8 avg SPEED
Conoco, Exxon, BP. Cetane: 40 - 48
3.5
67% Highway, 33% City

No carbon build up issues.

Bought with 10,000 miles. Was a dealership loaner.

[FormerRotor]

2011
335d
43,000 miles (mas o menos)
35ish mph (it's been reset a few times, but somewhere around there)
30./something mpg (again, I reset it all the time, but somewhere around there)
BP fuel
Sometimes 1.5/5, sometimes 4.8/5, avg: 3.9
65/35 (highway/city by mileage)

No carbon buildup as of yet as far as I know.

Additional: bought the car 01/31/12 with 12k miles. Mileage was at about 42.5k by 10/9/12

[GreekboyD]

Hey dzlmoose. Are you sure that your mpg is correct. I have the exact same mpg as you but I do 25% highway and 75% city.
Your mpg should be in the low to mid 30s based on your highway/city ratio.

[Jffeijao]

2011
335d
6,780 miles
39mph
29mpg
Sunoco 42 cetane
Driving style 3.0
65/35 (highway/city by mileage)

No carbon buildup as of yet as far as I know.

Additional:
bought the car Oct 2012 with 5,097 miles
No additives, no tune-ups
Car manufactured in Aug-2011

[cptcrunch]

2011
335d
30750
28.1
35.3
Shell or UDF (Mobil 1)
3.92
25% Highway/75% City

Carbon build up issue yes or no?
Not that I have seen.

Bought @ 15425 as dealer loaner.

[Puerto Rican 335d]

2011 build date June
335d
24k
22.7(depends on my week of treating her like a corner whore, LOL)
25 to 50 to 100 (Duh I RARELY use this and Im at work now,
Gulf although I used SHELL the one with Ultar Low Sulfur(which did not convince me)
3-5 depending on my mood!!!
10 % Hwy/90% city
yes , I beleived it got some cause last week I got and ENGINE and check engine light come up after I added 3 ounces of AMSOIL Injector cleaner and AMSOIL Cetane Booster, ALL went away after 2 half mile runs of 150 mph!!!!

Additional Info: Contary to what BMW states of adding additives I forgot to use the AMSOIL injector cleaner for a month( duh!!, I had some in the closet and forgot about it) Anyway as you read above with the CHRISTMAS lights on my Panel I suggest everyone should try it out.

[Got_Diesel]

2010 (Build Date October 2009)
335d
36,000
31.2-32.2mpg (Actual 32-34mpg)
30-35mph
Hess usually the most common, Cetane of 40-45
I usually drive about a 3.5 but I do open it up here and there, she gets decent WOT when merging
75%highway, 25% city. This is NYC traffic so you might consider that more city than anything

Not that I know of, she still runs great

Love this car.

[DnA Diesel]

2009
335d Sport
110,000km
31 Mpg (US)
~75km/h
Varied fuel (Shell, Irving, PetroCanada, Esso, Flying J)
3.5-4 driving
75% hwy / 25% city

No carbon build-up.

Had the car since new. Unscheduled repairs were replacement of left rear wheel bearing in 2010 and replacement of the DEF injector valve assembly.

[blackoil]

2010
335d
21480
27 mpg (actual about 28)
30.5 mph
Varied fuel
3.5 driving
50/50 city highway

No carbon problems that I know of.
Bought new in 11/10.
Mileage dropped about 2 mpg at ~5000 mi after the dealer did a software update. It has held pretty stead since then.

[Dr335d]

2011 335d sport package bought new 10/2011
15000
26 mpg
34 mph
Pride or Shell
3 to 3.5
rural town driving
no carbon issues that I know of, though some hesitation

[cssnms]

2011
build date Oct 2010
egr recall performed around 19k miles
26k miles
23 mpg
26 mph
Shell 99% of the time
driven hard - suburban driving/short morning commutes to train station
Carbon build-up issues - none - that I am aware of

[335dFan]

Model year - 2011
335d or X5d - 335d
Mileage - 8K+
Mpg (Please use the figure found in your BMW) - 30.1
Avg speed (Please use the figure found in your BMW) - 34+
Brand of fuel (cetane rating if known) - The cheapest I can find.
On a scale of 1 to 5 how hard do you drive? (1 meaning: I baby my car, 5 meaning: I drive like I am being chased by Cops.) - mostly 2-3, but I make it a practice to goose it at least once or twice per trip, either from 0-60 or from 60-100 where possible.
Highway/City Mix - Whatever it says below in my Fuelly signature block.

Carbon build up issue yes or no? Who knows, but I have been warned.

Additional Info: I use a modest amount of cetane booster/injector cleaner after each fill up. I had the EGR recall a few months ago. Did not notice any change in MPG directly related to the recall, but I can say that my MPG has been gradually improving over time even as cold weather has set in. Perhaps I am learning how to drive it in a smoother way.

[Vreimann]

Originally Posted by dzlmoose

With all this talk about the Carbon build up issue, I thought it might useful to gather some data. Whether or not you have experienced this issue or not please contribute. I think these are some of the key factors which are relevant to this issue.

Additional Info:

Model year 2011
335d Evolve Remap
Mileage 15000km
Mpg 8.9l/100km
Avg speed 48km/hr
Brand of fuel Shell V-Power
On a scale of 1 to 5 how hard do you drive? 2
Highway/City Mix 40/60

Carbon build up issue yes or no? No

[Thud]

So thus far, nobody has reported carbon build-up issues.

Model year - 2011
335d or X5d -335d
Mileage -29200
Mpg - 26.7mpg
Avg speed 33mph?? (will double check)
Brand of fuel - usually BP, unknown cetane
On a scale of 1 to 5 how hard do you drive? 3
Highway/City Mix - 40/60

Carbon build up issue yes or no? -None that I know of

Additional Info:
EGR warranty was done, but no other work has been needed. Definitely more reliable (knock wood) compared to my 135i with its fuel pump from hell.

[dzlmoose]

Originally Posted by Thud

So thus far, nobody has reported carbon build-up issues.

I guess the people who have had the build-up issues have not posted on this thread.

[montr]

Originally Posted by dzlmoose

I guess the people who have had the build-up issues have not posted on this thread.

How do I know I have carbon built-up?

[Robspages]

Yr: 2009
Model: 335d
Mileage: 40k
Avg MPG: 32.7
Avg Spd: 44.5
Fuel: Sunoco/WaWa
Drive type: 4
70/30 hwy/city. My commute is 37 miles each way with most of that being high traffic highway.

Carbon build up issue yes or no? Yes

Additional info:

Msg from BMW tech: "swirl flap linkage was binding and a large amount of carbon build is present"

I bought my D in June 2012 with 20k on the odo. I did nearly double that in the 6 months since.

[Robspages]

Originally Posted by montr

How do I know I have carbon built-up?

For me, parts started to fail all related to air intake and emissions. It started with the mass air sensor, then a thermal sensor, followed by some related codes. After those were clear, the Service Engine Soon light returned. Certain Subaru engines show a similar pattern when the turbos start to die: metal fillings from the turbos start to foul intake parts before thrashing around in your engine. With that in mind, I did some Internet searches (most pointed here and 'fest) and when the SES returned, I asked the tech to check for carbon/oil build-up or metal filings as that many parts dying in succession sounded fishy to me.

[cssnms]

Originally Posted by Robspages

Yr: 2009
Model: 335d
Mileage: 38k
Avg MPG: 32.7
Avg Spd: 44.5
Fuel: Sunoco/WaWa
Drive type: 4
70/30 hwy/city. My commute is 37 miles each way with most of that being high traffic highway.

Carbon build up issue yes or no? Yes

Additional info:

Msg from BMW tech: "swirl flap linkage was binding and a large amount of carbon build is present"

I bought my D in June 2012 with 20k on the odo. I did nearly double that in the 6 months since.

Would you do us a favor and post all of the fault codes from your service tickets leading up the final diagnosis?