Does anyone know for certain what triggers dpf regent and what the process is?

[nidgemo]

hi all - when I was buying my first e class (2008 w211) a few years ago, I got a lot of brilliant advice on here which really helped me out!

At that time I had been having a world of dpf issues in a Lexus, and was very keen to avoid the heartbreak again, which is exactly why I bought the w211 (last big prestige car not to have the f’ing things.

However, the time has come to change, and I’ve got my eye on a late 2013 w212 (facelift model).

Obviously, this WILL have a dpf in it...

So, two questions hopefully people with first hand experience will be able to help with.

First off, do these models have much in the way of dpf problems? I know it’s the nature of the internet to see lots of people with complaints but I’d welcome good and bad stories!

I DO do a lot of short journeys- leave kids to school, drive to the office, pop out for lunch, drive home, go out to the local shop etc - so I know my driving isn’t ideal, but I do love having a larger prestige car...

I know I’ll need to take if for a decent run every so often, and understand that, but that leads me to my second question...

If I’m only doing this every so often, I’d want to be sure I’m doing it right, which, for all I’ve searched, no one seems certain exactly the process...

Some say you need to be doing a regular speed for a certain period of time - if so, what speed? And for how long to complete the cycle? If you hit traffic and slow down does that cancel the regen, or reset the “time” back to zero? Some people say keep the revs high, some say drive as normal (obviously easier in an auto!)

Does the car indicate when you need to do this? A big problem in the Lexus was the first time you knew anything was up was when it told you it was blocked and went into limp mode! Does the E class tell you “dpf getting high, regen needed soon” or similar?

Really do like the car, so would really appreciate anyone with definitive knowledge or first hand experience.

Thanks!

 

[KennyN]

On my 2010 CLS the DPF does its clean when - the filter is full (measured by sensors) and the car is up to a certain temperature.

There is no visual indication on the dash to tell you that the process is running , the engine fan will run and you can feel the heat coming from the underside of the car as the filter is superheated to burn off the particulates.

I do mainly short runs ,of three miles maximum, and have had no issues with the DPF in the last 4.5 years of ownership , i always use V Power + fuel if that helps.

When mine starts the cleaning cycle i always let it complete by taking the car for a quick run along the motorway as switching it off half way through wont do it any favours.

Kenny

 

[nidgemo]

Thanks Kenny

Potential problem I have is living in rural Northern Ireland, my nearest motorway is 25miles from me, with potentially a lot of speed up and slow down in between... if I KNEW it was starting a regen I’d keep going, but I fear it could, if it doesn’t tell me, fall foul of me stopping regen a lot of the time without knowing

 

[Merkaholic]

The DPF syndrome is like doing the lottery....."you got to be init to win it" ........currently i have a 2009 cls for which i had the dpf removed (basicly the mesh has been broken) but prior to that i had a 2011 c200 cdi, the dpf never caused any issues. Both cars done identical driving which was 95% local......few miles each day. Basically In a nutshell its the luck of the draw.

 

[cheddar]

As above, it’s pot luck wether it works out for you or not.
It is calculated when to regenerate by lots of conditions, exhaust gas pressure (constantly learning and storing averages), exhaust temperature (at various points), engine and outside air temperatures, and even fuel level (it won’t regenerate if fuel is low).
If a normal regeneration cannot be performed, most cars usually enter a state where it’s constantly trying to regenerate around town and at low speeds, it stinks of burning and sounds different (increased idle speed/a bit lumpy).
It’s only when this also fails that you will then get a fault light on and a trip to the garage.
If concerned, and you don’t do many miles, why not give a petrol a second look?
A diesel only doing short runs won’t give fantastic economy anyway, with the engine taking longer to warm up.

 

[wu56Shoozz]

How Diesel Particulate Filters Work

 

[Deleted member 126251]

My wife has a 2015 B class and had her DPF frequently cleaning and making the racket that it does. Her trips were very short, driven in eco mode and at or below the speed limit ----. I was working away but now Im home, I often use her car and I always use the so called "sport mode" and drive it quite hard. I've also convinced her to drive it a little harder. That, plus the fact that we moved to a village and our trips are longer - we no longer hear the DPF - so I assume it is staying clean because the car is running hotter.

In retrospect, we should have bought a petrol engine because my wife mainly does very short trips.

 

[Thrash]

Not sure if it's true (would like someone to confirm?) but I read somewhere that the stop-start will switch itself off during regeneration i.e. the icon on the dashboard goes from green to orange. I have noticed this myself whereby the stop-start was active for part of the journey and then decided to deactivate itself on the motorway before becoming active again about 30/40 minutes later.

 

[w213e350damg]

i thought the late w212 were bluetec which means they dont regen just inject adblue to disolve the soot?? might be wrong

 

[Petrol Pete]

hi all - when I was buying my first e class (2008 w211) a few years ago, I got a lot of brilliant advice on here which really helped me out!

At that time I had been having a world of dpf issues in a Lexus, and was very keen to avoid the heartbreak again, which is exactly why I bought the w211 (last big prestige car not to have the f’ing things.

However, the time has come to change, and I’ve got my eye on a late 2013 w212 (facelift model).

Obviously, this WILL have a dpf in it...

So, two questions hopefully people with first hand experience will be able to help with.

First off, do these models have much in the way of dpf problems? I know it’s the nature of the internet to see lots of people with complaints but I’d welcome good and bad stories!

I DO do a lot of short journeys- leave kids to school, drive to the office, pop out for lunch, drive home, go out to the local shop etc - so I know my driving isn’t ideal, but I do love having a larger prestige car...

I know I’ll need to take if for a decent run every so often, and understand that, but that leads me to my second question...

If I’m only doing this every so often, I’d want to be sure I’m doing it right, which, for all I’ve searched, no one seems certain exactly the process...

Some say you need to be doing a regular speed for a certain period of time - if so, what speed? And for how long to complete the cycle? If you hit traffic and slow down does that cancel the regen, or reset the “time” back to zero? Some people say keep the revs high, some say drive as normal (obviously easier in an auto!)

Does the car indicate when you need to do this? A big problem in the Lexus was the first time you knew anything was up was when it told you it was blocked and went into limp mode! Does the E class tell you “dpf getting high, regen needed soon” or similar?

Really do like the car, so would really appreciate anyone with definitive knowledge or first hand experience.

Thanks!

Buy a car with a petrol engine. The type of driving you describe here better suits a petrol engine.

 

[CJD]

i thought the late w212 were bluetec which means they dont regen just inject adblue to disolve the soot?? might be wrong

Blutec diesel engines still need to regen their DPF's, Adblue is just a way to treat the exhaust gasses to help make them cleaner.

 

[CJD]

Not sure if it's true (would like someone to confirm?) but I read somewhere that the stop-start will switch itself off during regeneration i.e. the icon on the dashboard goes from green to orange. I have noticed this myself whereby the stop-start was active for part of the journey and then decided to deactivate itself on the motorway before becoming active again about 30/40 minutes later.

I was at the dealership today having my Airbag recall done, and funnily enough I asked this very question, and the chap confirmed to me that the Eco system does indeed turn off when the DPF is regenerating.
Hope this helps.

 

[Alex225]

As I understood if, a run of 20 minutes at over 50mph was the condition required to get the DPF up to the right temperature.

My other half has a CLS350 but only does the odd trip round the M25 to see family. I borrow her car once a month to pick up my daughter which is a 260 mile round trip. Should keep that DPF healthy, my E320 (03) doesn’t have a DPF but does 12k of just motorway driving.

 

[Deleted member 37751]

When driven at 60kph (42ish mph) for 20km (16ish miles) is when the regeneration kicks in on a BMW so I’d assume Mercedes won’t be much different.

 

[ph47mf]

I got a facelift W212 for about 2 years now, to be honest I couldn't feel there was a moment when I thought 'oh that's the regen' even though it must have done.

I do short school and work runs Monday to Friday (only a few miles each way), go to town (10 miles away) every saturday and either stay at home or go on a longer trip which require the motorway on sundays. I think my car sees the motorway once a fortnight. On my own I do drive a little quicker in sport mode and I put redex diesel in with every other full tank.

I recently had it remapped and the lad was going through my system info and it shows the DPF limit is 200 (not sure what unit it is) and mine is sitting at 80, so quite healthy he said. However he advised against just drive it really hard from time to time as the car brain would adjust and dump even more soot into the DPF, for it to auto clean you must go on the motorway and stick to the limit in lower gears so get it out of 6th or 7th if you think it needs a good run.

Not sure if I have been doing it right but no DPF trouble so far.

 

[David404]

You suggest you do lots of short runs which in turn does suggest that your annual mileage is on the low side. If that's the case the economy of the diesel is questionable and given the maintenance issues and not just the DPF...

I'd also be looking at petrol. Low miles, petrol, budget for a 2013 W212 - I might look at slightly older S Class vehicles, perhaps better availability in the S Class. Just a thought.

 

[RSTurbo50]

In the 9 months Iv hady E350 CDi Iv had no issues with the DPF. I do on average just 8-13 miles a day. Iv heard the V6 diesel rarely suffers DPF issues as it’s the smaller diesels on the A/B Class etc that seem to have the problems..

 

[HITECH]

Very interesting thread with peoples experience and input. My C220 CDI will not re-generate with the slightest error in the ECU for any reason. I have force re-genned it twice a year for the last 3 years just in case and my soot and ash content are very low and seem to stay low doing this. Preventative maintenance is simpler than a repair when a problem arises.

 

[SW18]

I’d advocate a petrol engine too: lower fuel economy but the cost difference is small if you drive small mileages. And with luck the engine should need less maintenance and be less likely to have parts failures. They reach operating temp much faster so suffer less wear from short trips.

The only issue is the lack of availability - hence the idea (above) of considering an S class; they are priced surprisingly low second-hand, a lot of car for the money.

 

[GreenLaner]

I realise I'm three years too late on this... but my 212 estate (is that a W- or an S-?) seems to struggle with DPF issues, and I've tried triggering the regen function using iCarSoft. The process it suggests is to drive at no more than 30mph/50kph, but above 2000 rpm for about 30 minutes. That's hard to do, especially in an automatic that changes gear even when in "manual" mode! I would have thought more speed/revs would be better to get the exhaust temp up, i.e. a motorway blast? The reading for the exhaust temp peaks around 200 degs C, which is about half what I've ready is needed to clear the DPF.