Can anyone tell me does the GLC diesel have a DPF?

 

Probably not applicable ln all countries, but safe to say required in most industrialized countries. For sure in North America, the EU and am guessing Australia.

 

It seems that you are right about Australia. The only problem I have had with my GLC came after about a week, when the engine light came on and the diesel particulate filter sensor had to be replaced. So I take it from that that it has one.

 

The GLC is Euro VI compliant and uses a Selective Catalytic Reduction (SCR) system where AdBlue is injected into an exhaust catalyst after it passes through a DPF.

 

Thanks..I presume there is not a notification system in place to advise the driver when a DPF regeneration is taking place.

 

An instrument cluster icon should illuminate.

 

Be grateful it was a defective sensor and not the dpf...otherwise big bucks to replace.

Ops, forgot. Vehicle in warranty. Bill M-B.

 

Precisely why I asked the original question.


I think that the car should warn when a DPF regeneration is required so that it can be brought for a long enough/hard enough drive instead of leaving it to chance!!

 

Pardon my ignorance (first diesel vehicle), but what is a "regeneration"?

 

Basically a Diesel Particulate Filter is, as the name suggests, a filter on the exhaust which catches and holds solid deposits from the exhaust gas.


After time this filter can become 'full' and needs to be cleared out.


This clearing out is a regeneration. It can be done by injecting diesel directly into the filter and burning off the deposits at a high temperature. This process is usually done while the engine is at a sustained high temp and needs a certain period of time to complete.


It is preferable not to interrupt this process by stopping the engine.


The presence of a DPF is one reason a diesel engine car may not be suitable for constant short commutes or city driving as the DPF may not get the chance at high temp to regenerate and the DPF can become clogged.

 

Thanks. I had done enough research on diesels before buying one to get the general idea, but hadn't heard the term "regeneration". People here tend to say "burning off".

What I still don't really understand is how adblue / bluetec changes this. Pre-purchase, the salesperson at my local dealer pretty much said that adblue / bluetec etc means that this is no longer an issue. But post-purchase that's not what the manuals and documentation say. At best it might be less of an issue than in a vehicle without adblue / bluetec, but you still need to exercise the car regularly it would seem.

Do you understand this adblue / bluetec technology enough to comment on what I was told vs what I have read? Is adblue / bluetec just about emissions reduction, or does it assist in the regeneration process?

 

Way out of my depth there I'm afraid!!


As you can see from my original post I wasn't even aware if my GLC even had a DPF.


My limited knowledge is from having learnt the hard way with my previous car when I had to replace the DPF!!

 

Hopefully someone who knows more than either of us (not hard) might chime in. I did a little searching, but ended up not much the wiser and more confused. There was a suggestion that in the Bluetec system, the AdBlue additive lowers the temperature required for regeneration, but I couldn't be sure that I understood this correctly.

In a number of systems using Diesel Emissions Fluid, it's injected in after the DPF, so I don't see how Adblue could assist in the regeneration process in such systems. But the Bluetec system is structured differently, and this is where I hit a wall, because it wasn't entirely clear whether Adlbue was being injected before or after the DPF in Bluetec.

 

There is a good explanation of the technology at:
http://www.dieselforum.org/about-cle...el/what-is-scr

 

Too my knowledge gassers have cats and diesels have dpf's.

 

The function of the dpf is to trap soot. A major pollution element of diesel exhaust. Regeneration injects fuel which combusts just forward of the dpf. This causes a large increase in temperature which in turn burns off the soot turning it into ash. At some point, usually based on mileage, the dpf will require removal, so as to remove the accumulation of ash. The filter will then be cleaned or exchanged on a one for one basis. Can't hazard a guess as to interval. The maintenance section of the operator's manual should address this.

If your driving at speed on the freeway/motorway and the dpf goes into regeneration no action will be required of the driver. There may be an illuminated icon in the instrument cluster indicating the dpf is undergoing regeneration.

If, however, your in an urban setting and regeneration is required it may have to be done manually. A icon will illuminate indicating regeneration is required. Actuating a dash mounted switch will put the system into regeneration. Or alternatively the ecu will intervene and put the system into regeneration. You will know this because engine rpm will spool up. As someone posted earlier, don't allow the regeneration cycle to be interrupted.

The difference in regeneration between highway and urban regeneration is the process requires heat that's generated at higher highway speeds. Unlike stop and go urban driving, where in some instances the engine does not reach normal operating temperature.

What I've posted above is is generally how the dpf functions. There may be some differences with the GLC 250D

The entire diesel pollution control system is complicated, expensive, maintenance intensive and at times, can be problematic. For example, failure to ensure regeneration is accomplished as required will in short order cause any number of serous failures all of which cause one's wallet to become lighter, much lighter.

My advice is to become familiar with the pollution control system as described in the operator's manual. And follow the guidance and maintenance requirements to the letter. In general, diesel cars require more tlc than gas powered ones.

I'm a big advocate of diesel powered cars and would have one myself if they were available in the US, however, wasn't in a position to wait until next model year.

PS. Almost forgot. If the car is parked and goes into regeneration make sure nothing combustible is underneath the car. Gets really hot.

 

I can only report on what I have seen customers experienced on both recent model MB disel passenger cars/SUV's and also recent model MB Sprinter.

No - there is no cluster notification on "Active" regeneration.

1) DEF systems - incl Mercedes - requires less "active" regeneration than earlier non-DEF systems.

2) B5 diesel (Euro diesel) also "limits" particulates - as compare to much "higher" particulates with B10, B20..

3) Yes - longer drive time at operating temp 1hr + kicks in "Passive Regeneration" where particulate system gets to full temp - passively "burns up" building particulates.

4) "Active" regeneration kicks in over total operation time/miles when Passive Generation is not keeping up with the particulates - and then Active injects diesel into that system to create the higher temp needed for "burn off". If Active Regeneration kicks in - which I have seen occur as "often" as 800-1000 miles - and is interupted - you will notice cooling fans on longer after shutoff - and most owners note a "smell" or "temp creaking" with the engine/exhaust system - in a MB Active regen it will auto restart next time the rig is started up - until it completes it's temp/burn cycle.

6) I have seen contaminated/poor-handling of DEF - I have seen B20 which is a very mixed-bag/wide-bad-quality in the US "overwhelm" the particulate system - I personally have not seen a B5 even B10 rig overwhelm a recent model MB diesel car/SUV.

7) In the comp recent model Euro diesels I have seen - I have not seen/noticed a Active Regen cluster indicator - I am not saying there isn't one out there - I am just saying I haven't seen it.

 

In my last 3 cars, VW TOUAREGs, there were DPFs but no indicator to notify when regen was active. I cannot find reference to one in the GLC.


Apart altogether from the functionality of the DPF...... is it not another emissions cheat?


The way I see it is the DPF stores the pollutant and then pours diesel on it and burns it and pumps it out the tailpipe when nobody is watching!!

 

Thank you for your response. I take it that you're a dealer, and so speak from a much wider range of experience that most here.

Are you able to attribute this to anything? My understanding is that the DEF is injected into the exhaust stream after the DPF, not before.

Are you saying that passive regeneration only kicks in after an hour? I read in the manual to drive at highway speeds for 20 mins once a month (which, if you read my earlier posts, was not the impression created pre-purchase by the salesman). I just tried to find this statement again in the online manual, but couldn't. I wonder if it's been removed as part of the ongoing editing.

This is one aspect that worries me, from what I've read. I gather that this additional fuel injected has the potential for oil dilution. Is that right?

We're told to bring the car in for service once a year or 25,000kms. If I was getting active regenerations on a regular basis, then I get the impression that wouldn't be soon enough, and more frequent oil changes would be desirable. Is that right? (If I was doing 25,000kms per year then I probably wouldn't be getting any active regenerations.)

There is no mention in the manual of such an indicator, although the engine warning light comes on if the diesel particulate filter sensor is triggered. I know this because I had a faulty sensor in the first week.

 

The emission control system has passed muster by government authorities in North America including California, with some of the strictest emission standards on the planet, the EU and Australia. So I think we can all be confident little soot is getting past the dpf.

 

I hear you....but the only thing I'm pretty confident of is that storing soot and then mixing it with diesel and burning it at high temp is probably not particularly eco friendly!


I would like to have the emissions tested while this process is happening and see what the outcome is.

 

Interesting concept, would like to see those results myself.

Would be interesting to hear from a California GLK Bluetech owner.

Had a GLC Bluetech been available in the US I would be driving one today.

 

I managed to screw up my above post. Somehow some of my response migrated into the quote. So you will have to read between the lines.

Sorry for the screw up.

Communication not my best feature.

Later will make an attempt to post my thoughts in such a manner that makes sense.