Thanks for the feedback. I neglected to also mention the company's comments that cleaned the device. Their initial flow test indicated a reading of over 10 which is max resistance. He expected the results to be around 8 after cleaning. The final reading was 6 and they had removed about 30 grams of material. I'm interested how you also interpret this additional information. Thanks!

 

I take some of that back. It was at 3.13g before, not 13g. Knowing that the upper limit is around 150g before you need to worry about cleaning, it was far from restricting flow.

You now have a new DPF essentially. The potential for issues will continue to be the sensors in the system.

 

Well it seems you have the ability to predict the future. So tell me where to go now. The CEL is on again. I haven't researched possibilities yet but off the cuff I'm thinking the pressure differential sensors. I'll look at parts availability later and will also confirm exactly what code it is although I'm fairly certain it's the same code. Any advice is always welcome. Feeling pretty defeated at the moment.

 

Sorry for your continued troubles. And don't feel bad, sensors are sometimes just "of the devil."

Let's double-check the code first, but yes; a good place to start may be the DPF pressure sensor. I think it also doubles as the DPF temperature sensor, but not certain.

It may also be that it could correct itself after a few start/run cycles, but I'm only cautiously hopeful. Chances are that a tune is the best (biased?) long-term solution, now that you've got a shiny, clean,basically new DPF. With the engine running optimally, no EGR, and little to no ash created, your Merc would live a long, happy life. The exhaust system sensors are just bound to cause headaches sooner or later, as is the AdBlue heater. When (not if) that goes bad, you'll be stuck with the "10 starts remaining" countdown and limp mode. For me, that was NOT an option.

 

I was going to tune it but they didn't want to write a tune that didn't increase torque and horsepower. I specifically asked and they were borderline rude and said no. I'd prefer to keep the sensors and am unclear what can and cannot be removed.

 

Understandable, we each have different goals and self-imposed limits. Might I recommend a different tuner, perhaps? I know of a few in total, some of which I’ve trusted in the past with my many TDIs.

I’d reach out to KermaTDI, or Malone Tuning as my alternate top choices.

As for removing sensors: not an option without the requisite software. That’s the whole point. New software tells the sensors to chill out and work more off of preset “safe” values. That way there’s much less variability and finickyness.

 

Thanks again. I'll race out to both companies and see if they can assist me. It's a fantastic automobile and I want to conquer the gremlins. Being that it's my daughter's car makes it a top priority. I'll let you know what I find out.

 

Hopefully one of them is able to do a custom tune. If so, it may likely require you to remove the ECU from under the hood where the airbox is and ship it securely to them. I didn't want to take that chance so I paid extra for the flash load tool so that I could do it myself. Alternatively, you may find an authorized shop nearby that works with either of these companies and just schedule an appointment with them to do it. I have no idea how much a custom tune may cost, so YMMV.

Agreed that it's a great little truck and what we really want is for it to be reliable. It's the wifey's ride, so I make sure it's taken care of. In my case, dealing with the failure points in advance of any great headaches has been worth it. The power is nice to have but you don't have to use it all the time. As I said, this is really how it should've come from the factory. It's that smooth and nice to drive.

Keep us posted.

 

The tuning has no options so far based on recent correspondence. Kerma does not have a tune available and Malone doesn't have any listed on their website. I inquired but I have not heard anything yet from Malone yet. Can you tell me specifically how your vehicle has been modified? Kerma gave me some guidance on sensors to look at but that was about it. Please continue with your guidance as time allows.

Many thanks!

 

Tuning companies usually have "off the shelf" tunes available, but they can also do customized work. There is more cost involved, of course, due to extra time. If none of them get back to you about a custom option, there may be others you can look at. The very first tune I ever got on my TDI was from a one-man shop called Rocketchip. The guy was extremely good but also extremely busy, and was difficult to get a hold of since he did everything himself. Not sure if that's still his modus operandi, but it wouldn't surprise me. He did tunes for all cars and trucks, including big rigs. Anyway... there are options is the point.

As far as being specific about the tune I have: I'm no software guy, but from my understanding, nothing as far as the functioning of the exhaust aftertreatment system is disabled, apart from the AdBlue system which I've turned off because of the failed heater. It still does regens as before, whenever called for by the ECU. However, specific expected values and ranges are changed in the ECU to make the entire system more....flexible shall we say, less uptight and overbearing. This is because the changes made to the engine management are so effective and as a result it runs very efficiently.

With my scan tool I can see EGR duty cycle is 0%, so the engine gets only fresh filtered clean outside air. The fuel rail pressure is increased as is the injection pressure. These pressure changes are well within the safety design parameters of each part involved. In addition, the two turbochargers put out increased boost to match the increase in fuel pressure and quantity, but there seems to be no fuel economy penalty for the added power. Instead, I'm seeing about 1-2 MPGs more than before. The new air/fuel mixture and slightly advanced timing burns cleaner, makes more power, results in less soot being produced and none being reingested through EGR. This also means your oil stays cleaner during the 10k mile interval. The rest of the engine internals benefit from the cleaner oil. It looks pristine under the oil filler cap and it's done 122k miles so far.

As long as you're not abusing it, stomping on the Go pedal all the time, you can't really tell anything has changed. But when you do, you need to hang on. The torque off the line is addictive.

 

I'll reach out to Rocket Chip to see if he's available. I'm getting a dead end with all other tuners. Malone told me to sell the car rather than tune it. My loyalty is wavering. Thanks again.

 

LOL, Malone has told me something similar. The Bluetec system is way overly complicated and problem-prone. He does like the BMW diesels better. Don't let that get you down...

I knew of the potential issues with the Bluetecs, and for more than 3 years I had no real problems. But once they start, it's difficult to pinpoint well and to fix definitively because the trouble codes and associated repairs are not well-documented. Not in MB service tech training and not in the independent tech world either. It ends up being a DIY that causes headaches.

That's why tuning it made more sense to me than going down the rabbit hole and still ending up with repeat problems. Since tuning it, I haven't looked back and haven't skipped a beat.

 

Andreigbs - many thanks for the great info you have posted here. It's timely because my wife's GLK has just thrown the 2002 code. There are no driveability issues and the car is getting great mileage.

If I grasp your approach correctly, I should throw a couple?? of cans of DPF cleaner into the tank and see what happens. If there is no improvement I'll contact OETuning/Malone (there are several in the Toronto area) and have a tune done. Sound right?

 

Just out of curiosity how many miles are on your GLK?

 

Pretty low 31K mi. My wife makes 1 or 2 highway trips each week but many more short trips (less than 3 mi) so I have been almost expecting the dreaded DPF code to appear. And here it is.

 

Have you tried clearing the code to see if it returns. Mine kept returning so I had my DPF cleaned. Afterwards the CEL came back so now we’'ve updated the ECM software. I pick it up tomorrow for testing.

 

Gents, the LiquiMoly DPF protector fuel additive is a great, cheap way to attempt fixing DPF-related troubles. It's also good preventive medicine. Then again, so are long highway blasts that clean out the DPF.

The best idea is to have a scan tool that can force DPF regens. First you have to clear any code(s), then run a regen and see if it comes back. In my case, I had a bad DEF heater that I didn't want to replace. No other problems with the exhaust itself. For such low mileage, it's most likely a crudded up sensor that's feeding bad info into the system and the code is the result. I doubt you have any hardware issues, like physical problems with the DPF or other items. Try to reset the code and run a regen. The site that has the LM DPF protector is idparts.com, just search for DPF protector. I think they're about $10 a can.

Srb, I'm curious what the new ECM software is and what it's intended to fix exactly. Hopefully your emissions issues will be resolved.

 

Here's what I know. All my sensors were within tolerance when tested. I then would drive the car back to my daughter (110 miles). On the third day she had it on two occasions the CEL would return. He was determined to find the problem on this trip. He used an online tech resource for other tips. Their consensus was to update the software to the most recent version. He actually had to update some of his equipment to be able to do this. He completed it today and is doing a final test in the morning after it's left standing overnight. If everything is good he's giving it back to me for testing. I plan to replicate as best I can the last two scenarios when it failed. First will be a 110 mile run at interstate speed. After that will be the short duty cycles of 3-5 mile trips. If it hasn't failed in 7 days I'll return it to my daughter. That's my plan so stay tuned for updates.

 

Yes, I've cleared the code and it came back. Strange thing though, the CEL came on just after a 150 mi highway blast and I assume a regen would have been triggered during that run. Intrigued by the ECM update, is it a TSB? Nice to see what effect it has.

Maybe I'll try the stealer and hit them with the ECM software update and their extended warranty on the soot particulate sensor. Seems worth a shot as a first step.

Andreigbs - Unfortunately my scanner doesn't have forced regen so that's not an option.

 

That's similar to when mine triggered except mine was 3 days later after some short trips. It is not a TSB.

It'll be interesting to see what the dealership says. Mine was out of warranty so that made my decision easy.

 

Knock on wood, but mine has been trouble-free (aside from the AdBlue heater failing last year) for 100 000 miles, the last 50 000 being city miles exclusively.

 

That's impressive. I'm all giddy this morning. Can't wait to get it back.

 

Back in the old days there used to be car enthusiast meet-ups, convoy style road trips and other fun-for-geeks events. Those were the days, when you could meet up with like-minded folks that drove cars like yours, where you could work on them together or just have a friendly competition to see who has the nicest model.

That was before people were too sensitive, too easily triggered or offended, and definitely before COVID...

Still, it would be nice to have a Get Together with other MB diesel fans. I bet there would be plenty to learn and share, maybe even get to the bottom of this complicated emissions system. I doubt we can find enough dedicated people though.

Srb, let us know how the new software runs. Karmikan, it sounds like you and I had the exact same problem with the AdBlue heater. I just used it as an excuse to get it tuned

 

Couldn't agree more. 1000 people can be perfectly happy and 1 person is offended, result - kill everything so we have 1 person happy and 1000 people unhappy. But I digress.

The dealership option is off the table, I'd get into a game of Russian Roulette. They do a scan, if the problem is the soot particulate sensor I pay nothing, if it's something else I pay for the scan plus any other "fixes". No thanks. From what I can gather from MB Canada, the ECM update might be a replication of the mandated European re-mapping which apparently de-tunes the engine and turns the car into a slug. Sounds really appealing.
Malone were helpful but can only offer a complete delete with hardware removal. Not at all keen but it might be my only option if there is no other viable solution.
Waiting for a call back from OE Tuning. Hopefully, they can offer a tune that keeps the hardware but re-sets the parameters so that the sensors are less twitchy.

 

I hate to be negative but I contacted several tuners and the answer was the same everywhere, No. I've started the first phase of my testing. I've replicated a delivery drive back to my daughter's house. So far I'm impressed. I can't tell any difference in the way it runs. Fuel mileage seems spot on if not slightly better.