DPF Failure - no warning - engine management light

[stewie]

please let me know your opinions in regards to DPF failure at 68k. 2004 (54) c220. no prior warnings. replaced but engine management light back on after 1200 miles and Bservice. only motorway miles.. causes??

 

[Alex Crow]

have a search on the dpf stewie, there has been a lot of chat on this lately and lots to read. sam unit knows more on this than me, but there is a software update and modified dps (differential pressure sensor) to cure this one. are you having this done under warranty?

 

[stewie]

unfortunately not.. as always warranty didn't cover a "service" part. not happy with dealer or warranty company! only had the car 8 weeks. local dealer couldn't get the car to clean/regenerate, it was past that. I had to buy a new one 570 + fitting. In regards to recent engine management light cleared but glow plug light is coming back on for few seconds each morning? dealer said it was sensor related?? not the new dpf. not been too reliable so far...

 

[lulu]

Did you buy it from a dealer? If so, I believe the onus would be on them to prove there wasn't a fault when you bought it.

Regarding it as a 'service' part is a little harsh given the sort of mileages they're supposed to cover, and you don't ordinarily think of having to replace a DPF.

Given your stated mileage and age I would argue there is a fault somewhere (even if the symptons only manifest themselves in the DPF). Has it been serviced with Low Ash oil, or cheaper stuff?

I've just tested my DPF (on a 2005 , 67,000miles) with Star and it's less than 10% worn out/full up.

 

[MB-Car-Tech]

Great point lulu,

the DPF on our Mercs are meant to have a service life of about 100,000km - and that is if the correct Engine oil has been used !!!

Low Ash Engine Oil is so important to these - what has been used ???

What were or are the fault codes generated???

 

[stewie]

thanks all, the car was given an engine oil and filter prior to purchase.. I drove it for just over 1000 miles and the eml lit up. I questioned the dealer regarding the oil used at the time " we only use the correct fully synthentic oils" etc etc. if only I could have proved it... it sounds like that was the cause then. Mercedes specialist in Cheltenham ( MB&B which have been excellent and I highly recommend ) said fault code was with dpf needing regeneration. Note to anyone looking to buy a car soon.. name and shame... purchased from Bristol Motor Company they were not willing to fix this neither were the warranty company which I paid extra for. I wouldn't recommend this dealer - all aspects of customer service and warranty company..disgrace. shame.

 

[lulu]

I wouldn't say incorrect oil was necessarily the cause, but wouldn't have helped matters.
Why would the engine be burning that much oil (assuming it's oil that's blocked it and not a poor combustion of diesel issue)?
Is there a mechanical problem yet to be established that's causing oil to be burnt, eg scored bores, broken rings, etc?

One of those things if you don't know it's history.

I'm pretty sure you'd have some recourse against the dealer.
If they're not co-operating, how's your stomach for litigation?

 

[Alex Crow]

I wouldn't say incorrect oil was necessarily the cause, but wouldn't have helped matters.
Why would the engine be burning that much oil (assuming it's oil that's blocked it and not a poor combustion of diesel issue)?
Is there a mechanical problem yet to be established that's causing oil to be burnt, eg scored bores, broken rings, etc?

must agree, the oil will not make any difference if the engine does not 'use' any. if an engine uses say 1L in 1,000 miles then the dpf will not last long - whatever oil is used...

 

[Alex Crow]

just had a quick look at esso/mobil oils. comparing 2x that had MB approval - one for just 229.3/5 and the other for 229.31/51 (dpf spec). both had exactly the same sulphated ash and phosphorus content, generally the low SPAsh oils are at most only 30% lower. have a compare yourselves, but there really is very little in it, and sometimes nothing :O

 

[Rory]

Great point lulu,

the DPF on our Mercs are meant to have a service life of about 100,000km -

Well that's 62,500 miles, so the OP's is pretty well spot-on.

How commonly are DPF's fitted on C220CDi's - I think they're pretty rare?

 

[stewie]

IF it was burning oil, wouldn't I get "add Oil message?

 

[haggettd]

My DPF had to be replaced at 67K miles but no management light came on at all. STAR diagnosed tha the ash content was too high.
MB direct replaced the DPF at their expense and did not quibble.
I would dispute the suggestion that the design life of the DPF is 100,000km since the tech data sheet and the service book don't call for a check on the DPF condition until 80,000km have elapsed. Then the next check is based on a calculation MB should perform based on Soot/Ash loading etc.
I don't doubt that some DPFs only last 100,000km and this has become the anecdotal life, but it is very premature indeed.

I did read somewhere that it was an offence (possibly in the US) to design a DPF system where replacement was required inside 150,000 MILES!

To have to stump up for a new DPF stinks.
Did the dealer service the car before they sold it? Did they check it out on STAR? Is there a DPF condition check report in the back of the service book?
Is there recourse under the sale of goods act anyone, you know, Goods not fit for purpose/not of merchantable quality etc.

If the DPF is a service item as they say, then why the bl***y hell didn't they service it before sale.

Did they sell it with bald tyres as well - no, of course not, you can see them - you can't see a DPF.

This sort of thing makes my blood boil as you can probably sense:twisted:

 

[Alex Crow]

yes, haggeted is our resident dpf fan by the way - just loves saving the enviroment at all cost.

 

[muhammad]

Sounds like incorrect oil has been used..you ve got to use 5w/30 low ash oil c4,noting to do with burning oil dpf general works on high temp low ash protects the dpf,thats the reson you have to use low ash oil....

 

[twistedsanity]

i have a dpf, just hit 60,000 miles and no eml yet, services are done by a friend and i buy the oil but in the servicebook on one service(by the previous owner) done at a main stealer they didn't use low ash, where are they fitted and are they a diy replace or is it major work?

 

[Rory]

in the servicebook on one service(by the previous owner) done at a main stealer they didn't use low ash,

This has cropped up quite frequently. Quite bizzarely, the dealers don't seem to realise that they need LA oil.

 

[grober]

DPFs are a major problem waiting to happen in many modern diesels. So much so that manufacturers are starting to put disclaimers on their model product descriptions. Problems seem to arise with short journey times when the filters don't have time to warm up. Once up to operating temperature there is usually an fuelling routine built into the engine ECU to assist in burning off any accumulated particulate matter. With short journey's the DPF never gets hot enough to burn off the accumulated particulate matter and it chokes. It's recommended to have a least one old fashioned "burn up" a week if most of your journeys are short. http://www.theaa.com/motoring_advice/fuels-and-environment/diesel-particulate-filters.html

 

[Alex Crow]

the 'wrong' oil causing premature failure is just a myth, oft repeated yes, but wide of the mark. grober's point is much more relevant with the dpf ash clogging issue. why do i say this?

it's funny we hear so much about how important the oil is, but no-one picks up on the effect of different fuels? if you look at say a typical distance between services of 15,000 miles, a car may combust 1200 litres of fuel, the products of which all pass through the dpf. in the same period it may only combust 1 litre of oil. combustive products of fuel are the main causes of dpf ash content. but regardless of this, the difference between an MB certified low SPAsh oil may well be non existent, they may both have the same specs!!! other issues include out of range sensors, blocked air filters, failing turbos, software versions etc. not to mention the effect of short, low speed driving cycles as per grober's post.

ok, so kill me.

 

[Rory]

they may both have the same specs!!!

That wouldn't surprise me - I have it on good authority that Mobil 1 and Mobil 1 Turbo Diesel are the same oil but in different cans for marketing reasons.

 

[haggettd]

Good points AP, well made as usual.

I guess the only thing we can reasonably control is the oil we use.
Purchasing the correct oil is a straightforward task provided you know exactly which spec you need.
How on earth MB technicians put the wrong oil in is quite beyond me - it's in Black and white, even I know what my car needs. My car's had the wrong oil 3 times in its life - all MB services.
It's a good thing using the 'wrong' oil doesm't make a lot of difference. Ordinary oil contains about 1.5% ash and low ash oil contains about 1% (30% less - not a fat in real terms)
I've just bagged 10Litres of Mobil1 ESP for £51 off ebay which I will supply for my next service - it's the only way to have confidence in what's put in.

DPFs are increasingly common now - it's harder to buy a new diesel car without one. Now with Bluemotion and Bluetec you have to drive around with a second tank full of urea solution which is dosed in with the fuel - added complication. The owner may remain oblivious to this until, like with DPFs - the system goes wrong.

It seems to me that Diesel is steadily losing it's appeal as its traditional virtues of simplicity and reliability and low running costs (servicing repair etc) are being wiped out by new emissions technology. Diesel used to be much cheaper than petrol and now it's the other way round.

MPG may get the headlines but the whole life costs are what really count.