W212 BlueTec CEL

[Bob338]

Son-in-law took over my old 2011 W212. 90K miles. While visiting last weekend the CEL came on. He's taken it to two shops in Sacramento area. Both say the DEF heater is bad as is one of the NOX sensors. Both common problems, but one suggests replacement of the entire DEF tank and guts while indicating it has been 're-engineered'. Much more expensive by about $1000. Others with the same experience have suggested he go to a shop, the author of the following blog. I've heard the name on this board but don't recall in what context and whether good or bad. Anyone remember? Any suggestions for correction of the problem?

Mercedes-Benz & Sprinter BlueTec Diesel Issues/Problems | Stephens Service Center - Sacramento's Best Mercedes-Benz Service & Repairs

[engatwork]

Wow, after reading all that I'm glad I got the gasser GLK. Have you thought about trying to find a 98/99 E300?

Wonder if big rigs with DEF have these type issues?

[Bob338]

Originally Posted by engatwork

Wonder if big rigs with DEF have these type issues?

Haven't checked myself but I've been told the problem is a common one in the US diesels. One friend directed me to a Cummins diesel forum in Dodge pickups, but it didn't interest me.

Besides that car, which was mine at one time, and my 190D W201, I'm now in a GLK 350 Blue Tec with 40K miles, so I do have concern for the issue. Had this car since new and have never even had a minor warranty claim and no CEL issue. I'm considering the recommendations in this blog for use of the Red Line motorcycle oil. I was steered to Red Line at the factory in '82 where I picked up a W126 diesel. The factory rep at that time recommended use of Red Line diesel additive, advising it was the ONLY additive approved and used by M-B, which makes this oil recommendation more acceptable. Shops at that point had what they called "the Red Line treatment", which was to run Red Line throught injectors to clean them. Never did it myself and never had problems.

Still need to know about this shop!

[alipak]

I spent a bundle of money on my 2011 GL350 Bluetec on this issue and finally went backwards to a 06 CDI and never have looked. Never again anything with DEF for me.

[MB_FanAddict]

Never having owned a Bluetec w/DEF, I don't know if there are any TSBs out on the W212's DEF system or if there is in fact an updated/improved DEF tank. If it was my car I would find out if there was actually an updated part available, otherwise would just replace the heating element. I believe MB requires the DEF tank be flushed out at periodic intervals though. The NOx sensor of course, is what it is.

I will say I've found quotes from independent shops (at least in the Atlanta area) not all that cheaper from one of the dealers and then you have unknowns with aftermarket parts, little recourse when problems arise and often no loaner.

The article on the Stephens Service Center site has some good points I think (fuel additive use, engine oil flush with unknown maintenance history, air filter changes, software updates for the ECM, owners not wanting to properly maintain their vehicle), but I certainly don't agree with all of it. Like "Ignore the oil leaks. Continue to change the oil & air filters, but just drive it until it blows up" What kind of advice is that? Also, I feel some of the potential issues are blown way out of proportion unnecessarily scaring people.

For commercial or severe service a heavier weight HD oil may (or may not) be beneficial. There are 5w40 oils that would still protect the emissions system (FCA now recommends 5w40 Rotella T6 in the EcoDiesels), but I certainly would not advise using a 10W60 or 20W60 motorcycle oil!

I don't plan on driving my E320 CDI forever and will eventually upgrade to a newer diesel (if I don't opt for a smaller model). At some point a CDI is going to need expensive work as well, so I'm not sure going backwards is really a solution.

[shertex]

My plan is to drive my 06 CDI forever and expenses are what they are. But if I were to get something newer some day I would probably opt for a 14-15 E250 Blutec....currently in the $25k and above range.

[Bob338]

Originally Posted by MB_FanAddict

Never having owned a Bluetec w/DEF, I don't know if there are any TSBs out on the W212's DEF system or if there is in fact an updated/improved DEF tank. If it was my car I would find out if there was actually an updated part available, otherwise would just replace the heating element. I believe MB requires the DEF tank be flushed out at periodic intervals though. The NOx sensor of course, is what it is.

I will say I've found quotes from independent shops (at least in the Atlanta area) not all that cheaper from one of the dealers and then you have unknowns with aftermarket parts, little recourse when problems arise and often no loaner.

The article on the Stephens Service Center site has some good points I think (fuel additive use, engine oil flush with unknown maintenance history, air filter changes, software updates for the ECM, owners not wanting to properly maintain their vehicle), but I certainly don't agree with all of it. Like "Ignore the oil leaks. Continue to change the oil & air filters, but just drive it until it blows up" What kind of advice is that? Also, I feel some of the potential issues are blown way out of proportion unnecessarily scaring people.

For commercial or severe service a heavier weight HD oil may (or may not) be beneficial. There are 5w40 oils that would still protect the emissions system (FCA now recommends 5w40 Rotella T6 in the EcoDiesels), but I certainly would not advise using a 10W60 or 20W60 motorcycle oil!

Appreciate your observations. Your first paragraph is EXACTLY what I have suggested! Still doing research on the oil. Some of that in the blog makes sense to me. All except the viscosity. Particularly for short trips around town that doesn't seem appropriate but then the basic weight cold weight should provide all the lubrication required without undue wear for any short, town driving. The heavier 'hot' weight seems appropriate for our summer desert heat also. Intriguing!

My last couple of diesels came from a dealership in the Sacramento area though factory delivered. One of their service advisors and "Asst. Service Mgr." was the goto guy for MB-USA for the Sprinter motorhomes being driven to Cali from the builders in the Midwest. They started having the same CEL problems in 2008. The guy is VERY knowledgeable and I've referred such problems from users on other forums to him. All have been quite pleased with results. He's on vacation now so I haven't had opportunity to talk to him but early on he discounted the cleaning out of the DEF tank and claimed never to have seen the crystallization of the DEF which folks claim has caused problems. I've seen nothing of it either though admittedly not able to see inside the tank, but none of the spillage, nor in the partially used bottles in my garage have ever shown evidence of the crystallization.

Thanks.

[TimFreeh]

MB only requires the DEF tank to be flushed if the vehicle is a low-mileage example that doesn't use the DEF in the tank over extended periods of time. Can't remember the specifics but I think DEF has a 24 month shelf life, in normal service where you're driving the car 10-20K miles a year its a non-issue.

I've got 100K miles on two OM654 engines with the Bluetec system and, to date, I've had absolutely zero issues with any emission component of the system. There are quite a few ideas presented in the linked article that don't make any sense to me at all.

I do see how low-milegage Bluetec cars that were operated in stop-and-go city traffic exclusively could have issues - its very difficult to do a complete and efficient DPF re-gen if the system has to work with low engine loads in cold climates. Don't think I'd be looking at a Bluetec if I was a city dweller, but I suspect most Bluetec owners aren't low-mileage city type drivers.

I'm not crazy about the DEF and DPF components but at least for me they've worked flawlessly so far. Not sure they'll go 300K miles without any issues but I'm hoping to give it a try.

[97 SL320]

Originally Posted by MB_FanAddict

The article on the Stephens Service Center site has some good points I think (fuel additive use, engine oil flush with unknown maintenance history, air filter changes, software updates for the ECM, owners not wanting to properly maintain their vehicle),


but I certainly don't agree with all of it. Like "Ignore the oil leaks. Continue to change the oil & air filters, but just drive it until it blows up" What kind of advice is that? Also, I feel some of the potential issues are blown way out of proportion unnecessarily scaring people.

.

Get a price on an engine out total reseal and you probably would agree with him. I actually don't know the exact numbers, but if a shop hit a customer with a repair that was 25 to 50 % of the cars value, it would be a tough sell.

This would be followed with the customer asking ( demanding? ) that only the active / large leaks be fixed. The shop battles the leaks, something else starts to leak down the road and customer complains " the leaks you fixed XX months ago are leaking _AGAIN_ I want it fixed for free ! ( even though the leak is from another source. )

{Once the engine starts leaking oil, there is no cheap way to fix the problem. I’ve actually come to the conclusion, owners are better off if they ignore the oil leaks. Continue to change the oil & air filters, but just drive it until it blows up. Oil leaks are “generally”, too expensive to fix right.}