Diesel Particulate Filter maintenance

[GinP]

It's time to replace my E320CDI Estate and I would like a used E350 CDI Estate (post 2009 model), as I particularly like the six cylinder engines, but I am dithering.

First:- I have now reduced my motoring from 12k miles per year down to about 7-8k mile,pa and I am wondering if this is a recipe for getting a clogged up DPF and the attendant high cost of repairs- Perhaps a regular infusion of 'CataClean for Diesels with DPF' would reduce the risk?

Secondly:- a subject which only time will tell- I live within the M25 and the London Mayor seems to have his sights set on diesel car owners- as does our Government more widely, especially as the UK has been threatened with stiff penalties by the EU for not achieving required CO & NO2 emissions.

I don't want to buy a car with the risk of its value plummeting if Road Tax or other penalties are hiked to unacceptable levels and that has to be my decision but it would be good to know if the DPF issue can be easily contained?

Any advice on that topic , please?

 

[W210Virgin]

Particulate issues relate to driving speed not annual mileage. If your average speed is high enough you'll be OK. Given that you're inside M25 that's not that likely so you may want to think about a petrol engine. Also, the economics of diesel vs petrol at that annual mileage just don't stack up, regardless of how fond you might be of a torquey 6 cylinder.

Sent from my SM-G935F using Tapatalk

 

[horatio]

I really can't see the point of a diesel with that mileage.

Only problem, a quick look on AT shows only two V6 petrol 212 estates for sale in the whole country so you might have to be a bit patient!

 

[400ixl]

Given the mileage and where you live I would get a petrol.

If you must get a diesel then provided you do a decent 20 minute plus drive every 300 miles or so the DPF should not be an issue.

 

[Rory]

Does anyone know (with respect, not just a guess) how dpf regen really works in these cars?

Reason I ask is that my wife's VW Tiguan (and I gather this is the same for all VWs, and many pother marques) it never passively regens - in UK use the dpf doesn't get anywhere near hot enough. Yet VW UK and dealers insist it does passively regen.

What happens is the dpf does an active regen based on soot load. If this hasn't happened for 465 miles, then one is triggered anyway. So you can do a long, fast run, then get in to go to the shops the next day and it'll start an active regen. This business of taking it for a thrashing now and again is pointless.

The only thing that's a bit of a pain in her car is you can't tell it's doing an active regen until you stop the car and get out - then you can hear the engine fan and you become aware of the "smell" of the very hot dpf. If stopped, it restarts next time the car is used. It takes about 10 mins so it would be a bit of an issue if you used the car in 5 min bursts!

 

[ashenfie]

Does anyone know (with respect, not just a guess) how dpf regen really works in these cars?

Reason I ask is that my wife's VW Tiguan (and I gather this is the same for all VWs, and many pother marques) it never passively regens - in UK use the dpf doesn't get anywhere near hot enough. Yet VW UK and dealers insist it does passively regen.

What happens is the dpf does an active regen based on soot load. If this hasn't happened for 465 miles, then one is triggered anyway. So you can do a long, fast run, then get in to go to the shops the next day and it'll start an active regen. This business of taking it for a thrashing now and again is pointless.

The only thing that's a bit of a pain in her car is you can't tell it's doing an active regen until you stop the car and get out - then you can hear the engine fan and you become aware of the "smell" of the very hot dpf. If stopped, it restarts next time the car is used. It takes about 10 mins so it would be a bit of an issue if you used the car in 5 min bursts!

The cleaning of the filter is known as ‘regeneration.’ Regeneration is simply a fancy name for burning off the soot from the filter. This soot gets burnt off due to the fact that exhaust systems (which exist to carry the leftover gases from the engine’s exploding fuel) naturally get very hot when you drive the car continuously for any length of time.

This ‘passive’ regeneration occurs continually, and will generally go unnoticed by the driver.

However, many drivers don’t go on long, uninterrupted high-speed journeys. In certain circumstances (e.g. after frequent short journeys or slow driving in congested areas), automatic regeneration may not occur. Therefore, the filter begins to clog.

When the engine computer (ECU) detects that the filter is more than 45% clogged, a second process starts, called ‘active regeneration’.

Active regeneration means that the ECU tells the injectors to squirt more fuel into the engine. Because diesel engines are controlled by the amount of fuel being injected, the injection of more fuel makes the engine run faster and hotter. The ECU keeps the engine running faster and hotter for about 5 – 10 minutes. This process will normally clean the filter.

However, if the process of active regeneration is interrupted (e.g., by finishing your trip before the process is complete), the filter may not be completely clean.

If unsuccessful, the ECU will try and repeat this process for a further 15 minutes. If the filter is still clogged, the DPF light on the driver display panel will then be lit.

If the owner is lucky, simply driving at a constant speed of at least 60 km/h for about 10 minutes will solve the problem.

If not, the vehicle’s dashboard will display messages indicating that there is an engine management fault and DPF fault. The engine will drop into ‘limp home’ mode, or, sometimes, break down entirely. At this point the vehicle will have to go to a garage to have the filter professionally cleaned, which won’t be cheap. Occasionally, the entire DPF filter will have to be replaced, which will be very expensive.

 

[Mr Filipov]

Generally speaking if you know what you are looking out for and know what measures to take there will be no problems really. My DPF for example does a regen once a week, roughly the same day as such depending on use. Mainly town driving for me with no issues so far. Seems to occur every ~300 miles at the current rate. Usual signs of a regen running, at least on mine: change of the engine note, feels a bit under-powered for the time being, gear changes happen at 2k even in eco mode, idle rpms at 800, a lot of heat from underside of the car and exhaust (which is only noticeable when outside of the car).

 

[markjay]

My other car is a Kia Diesel that does less tan 1,000 miles a year.....

The Kia owners forum suggested that using premium Diesel fuel will reduce incomplete burning and will slow down the process of clogging-up. I have been using Shell V-Power and had no issues over the past 3 years. Not very scientific I know, but these are the facts - make of it what you will

Said that, last month I drove the car to Paris and Back (I am not sure if it has ever seen a Motorway before ) and this almost certainly cleaned the DPF

 

[MancMike]

Have you considered a 350 petrol? I'm on the hunt for an E350 CGI as I don't like diesel, but should solve your problem too, although they're quite rare in finding.

 

[pembssurf]

Have you considered a 350 petrol? I'm on the hunt for an E350 CGI as I don't like diesel, but should solve your problem too, although they're quite rare in finding.

That's 3 of us then and only 2 for sale in the entire U.K. Haha..


Seriously. I have been looking for either a c350 CGI estate or an E350 CGI estate for over 6 months now and not found one! Rarer than rockin horse poo!

 

[Rory]

This soot gets burnt off due to the fact that exhaust systems (which exist to carry the leftover gases from the engine’s exploding fuel) naturally get very hot when you drive the car continuously for any length of time.

This ‘passive’ regeneration occurs continually, and will generally go unnoticed by the driver.

However, many drivers don’t go on long, uninterrupted high-speed journeys.

It's the "get very hot" bit which seems to be the main contentious point with VW (and other makes) but I'm keen to understand if MB is the same.

With any diesel in the UK, they're bumbling along effortlessy at 70ish at around 2K rpm. With lots of airflow the dpf in VWs has been recorded at 250C - nothing like hot enough to regen. There is a move to integrate dpfs more into the engine so they run hotter, but of course that makes them more difficult and expensive to replace.

My DPF for example does a regen once a week, roughly the same day as such depending on use. Mainly town driving for me with no issues so far. Seems to occur every ~300 miles at the current rate. Usual signs of a regen running, at least on mine: change of the engine note, feels a bit under-powered for the time being, gear changes happen at 2k even in eco mode, idle rpms at 800, a lot of heat from underside of the car and exhaust (which is only noticeable when outside of the car).

Thanks - that's the same as our Tiguan. I have to say if it happens when driving I can't tell, although as it's my wife's car I don't drive it much so am perhaps not tuned in to subtle changes. I have got out of it a couple of times and found it mid-regen.

 

[MancMike]

That's 3 of us then and only 2 for sale in the entire U.K. Haha..


Seriously. I have been looking for either a c350 CGI estate or an E350 CGI estate for over 6 months now and not found one! Rarer than rockin horse poo!

Yep, I'm after a saloon, which seem about as rare as the estates. Coupes are more readily available. I can wait for the right one though.

I had a thread a few weeks ago and people were managing to find a few including an estate. I was just looking on auto trader, but there's quite a few of you broaden your search to dealerships, eBay, etc.

 

[Graeme_m]

Like the OP, I also live within the M25, and have an E350 CDI estate (212). My driving consists of quite a few short local journeys and two or three longer (50 mile) journeys per month, plus an annual trip through Europe. Never had any problems with DPF although once or twice has gone into 'active regeneration' mode. My mileage is also reducing to circa 7,500 miles per year and I am looking to change for an E63 estate, given the lack of any other petrol equivalent.
And, I cannot get my head around the idea of buying into a hybrid at an extra (high) cost, only to lose up to 15% of load space into the bargain!!