I figured I'd get the ball rolling on this topic. Many owners of the E90 335d who can be found on other forums have been grappling with excessive carbon build up. Now many would agree that diesels by design will have some carbon buildup, however the US models seem to suffer from problems not seen by our European/UK bretheren. I wonder if BMW knows why this is happenning and if so why they haven't chosen to tell us. If it's a fuel quality issue (low cetane diesel) then owners can mitigate that to some degree with an additive such as biodiesel or a product which contains 2EHN. Perhaps it's a problem related toUS emissions targets which require heavy amounts of EGR for our vehicles. Is there a silent recall on the cleaning where if you get an SES they'll do it without charge or only if you're under some sort of warranty (Factory or Extended). Regards,
Yes this is a growing issue for the M57Y engine sadly. BMW is stating it is due to low diesel fuel quality that america has. They have how ever just came out with a new procedure to clean the carbon on the valves and tangeal ports (hardest part to get to). They will be using crushed walnut shells at high pressure and special scrapping tools. No longer will intake need to be replaced and the cylinder head does not have to be removed. As for recall or assistance from BMW they isn't much news on that. I know they have been helping people with this repair (of course this is up to there discretion). I do find that people who ride there diesel hard they really haven't been having this issue compared to people who just puts around in it.
Hmm. Interesting reason/excuse. Of course we'd like to hear the science behind their statement regarding diesel fuel quality. I recently heard about tools designed to walnut blast the M57. Surprised it took BMW years to design them. Price hasn't yet been released.
Our fuel is less filtered and does not meet the minimum scar test used by pump manufactures like Bosch. Part of this is in the distillation process. In Europe diesel is the predominate fuel with gasoline being the by product of diesel production. In the US the reverse is true further hindered by EPA restrictions on the sulfur content. Refineries are supposed to be making additions to make compensate which has been proven in random testing doesn't always happen. BMW needs to step up to plate and offer the same extended warranty coverage 335i owners received. With tighter CAFE numbers BMW will be hard pressed to meet unless they have happier diesel owners.
Less filtered? I'm not sure lubricity (wear scar) should really have anything to do with carbon buildup. Perhaps injectors are fouling (low detergent) or maybe it is emissions programming for the US.
Nothing I've read has indicated that the absence of scar test requirements has anything todo with our problems. In fact, because almost all diesel in the US has some bio-diesel in it, wear (of the fuel pump) has not been an issue (as it was in VW TDI.) In any case, that has nothing to do with carbon build-up (CBU). The EU has lower sulfur requirements than the USA/CA - 10 PPM rather than 15 PPM, so that is an entirely non-starter to our problems. To some degree, I believe that the low fuel standards in the non-California states (all 37 of them) is part of the problem. The CA States have generally better fuel - usually 51 Cetane, with better control of other aromatics and such - and I have seen fewer posts of problems with CBU from those states (very subjective, but still.) Also, note that the X5D have had fewer problems; apparently due to heavier engine loading and the prescense of the low-pressure EGR system on those engines. BMW does need to step up for the 10,000 335d owners.
I forgot about this thread - too many forum syndrome. It's SI B11 03 14, and is a pretty complicated proceedure that involves special walnut-blasting wands, removing the intake manifold, and other arcane stuff. I believe it's scheduled for 3-4 hours of tech time. If inquiring minds want to know, I've got the pdf and can upload it.
I would say quite a bit more since the valve cover has to come off as well. Plus there is a lot of scrapping needing to be done since it is much more gummy than other carbon.
I have had the walnut and scraping done. Along with the EGR recall. My issue is also with leaking injectors and a miss at idle. I have has injectors replacement 4 times now. I also heard something about a DDE or DDM replacement. I am higher than most on mileage ( 69k) so have been at the forefront on a lot of these issues. Yay for me!!! Luckily I am CPO but come 100K I am out !!! But what to get??? For my 50th??? Currencydog
I may be having to face the carbon build-up coming up on 70K miles on my '09 335d.. That's what the diagnostics are calling out...the walnut cleaning. Aside from the "Check Engine" light I recently had a more serious flag: "Engine malfunction" which then switched the engine to the limp home mode. This flag cleared on the next start-up. Another symptom is a slight hesitation occurring during first acceleration after the car has been sitting overnight. Could this be related or another unrelated problem?
I just got the word, today, that my 80,000-mile 2011 335d has the carbon problem. They're proposing a sandblasting procedure. Does anyone know about the attributes of walnut-blasting vs. sandblasting? They're estimating a cost of $2400. Yet another disappointment. I bought my first diesel, and made it a BMW, thinking the motor would last forever. I've followed Mike Miller's Lifetime Maintenance Schedule to the letter, at enormous cost. For a fraction of the cost, I would have had far better service life from just about any other car on the planet.
Seems like we are in the same boat! No doubt your service provider was using the term "Sandblasting" in a generic way. the SI B mentioned earlier is very detailed and specific. Walnut shells are just one of several different media used to 'sandblast'. They are bigger and softer than grains of sand, and therefore less damaging to machined or polished surfaces. I've not given the go-ahead to my dealer yet. Looking for more feedback on the process. I have not yet elevated my displeasure to higher 'pay grades', pending the outcome.
Of course I wish these types of unintended-consequences of modern direct-injection designs weren't an issue, it is indeed frustrating to be facing the hassle &/or expense to correct the carbon build-up from d.i. engines. I'm guessing there's 3 routes - the dealer, a qualified independent shop (who might do it for less than the dealer - see the pinned post at the beginning of the Member Introductions sub-forum for leads on finding indy shops), or the d-i-y route. I believe Bavarian Autosport offers rental of the walnut-blaster setup for anyone wishing to tackle the project. That's perhaps the least out-of-pocket route, but takes the most of your time, and of course needs to be done correctly. http://blog.bavauto.com/15543/bmw-d...take-ports-and-valves-de-carbon-walnut-blast/ It would be interesting to compare gas costs for the same mileages, gas. vs. diesel. Diesel costs more, but, theoretically, better mpg. With the torque-monster E90 335d, I'd probably blow that out the window with the fun of all that off-the-line torque in around-town stop-n-go driving, but that's me. Anyone who moderates that & is mostly highway miles, might find some gas savings there - if so, then the question would be is approx. $2400 or more saved over 80k miles, answering whether mpg. savings might help to make it a break-even proposition or not for the necessary maintenance procedure (obviously that excludes all other various costs). There are a few intangibles, such as safety - if the car was totaled in a horrific accident but spared the occupants life-threatening injury, engine-maintenance expense aside, I'd guess most might be of the mindset sruvivability outweighed the maintenance expense that allowed them to be in the vehicle up to that time. That's theoretical though and such judgments are to each their own. I'm not sure if it's something that's particularly established, but there perhaps is a perception problem for BMW - it gained a reputation of having extremely long-lived, fun-to-drive vehicles out of it's cars of the 70's & 80's. As BMW's have gotten ever-more complex (obviously, BMW isn't the only company, either), it becomes ever-more expensive to run & maintain them into the higher mileages that the simpler driving machines of past years attained with a seemingly lesser-degree of expense & hassle. Not that any of past bimmers excelled in that regard, it just may seem more-so with 20-20 hindsight. It would seem there is a price for progress, but, that also discounts the tangible & less-tangible inherent elements of that progress. Oh well, none of that gets your engines walnut-blasted... will be hoping for the best, whatever it needs to be! Here's a tongue-in-cheek view of German reliability - various truths, yes, but also exaggerations (at least, in my experience - still, a fun read). http://dougdemuro.kinja.com/german-reliability-the-greatest-myth-ever-sold-to-amer-1572026115
My, now sold 335d, was approx. $1100 more expensive than a similarly equipped 335i and I broke even at around 55k miles. . If it weren't for the unresolved emissions issues during the last year of ownership and the looming bill for a carbon cleaning sometime in the future my wife might have agreed to let me pay off the car and keep it. Sure I had the extended warranty but only 1 year left at the time. 435i is nice but I sometimes wish for my old diesel.
My Check Enginge Light just came on (2011 335d with 45K). I shudder to think that the fix will be $2400 to blast the carbon off with crushed walnut shells. Time for BMW diesel owners to demand BMW take care of this as we were sold on the reliability of the diesel engine. In light of the VW diesel scam, I would think BMW would want to make their diesel owners happy and not fall into the pit with VW.
