How quickly can a DPF get clogged up?

ratechaser

So, I have a 5 year old S Max, no major issues to date, all servicing & MOTs done by the main ford dealer I bought it from (new). 1 week ago, get an engine malfunction warning, car initially cuts out, but restarts and quickly goes to limp mode. I book it in to the dealer to look at a couple of days later.

Dealer tells me that based on diagnostics, a new fuel filter is needed, then a DPF regen. Ok, fine.

However after doing this, the dealer tells me that the car won't regen as the DPF soot loading value is at 440%, which is pretty extreme, and requires a replacement DPF (at silly ford prices, but that's another matter).

So my question - can a DPF get that badly clogged up really quickly? As I understand it, the car should have gone into limp mode as soon as it got to 200%, so either it's got massively worse in the 2 days since the car initially gave me a warning, or I'm thinking there's something else going on here around engine management not working properly.

And no, I won't be paying ford prices, I'm just a bit narked that without any warning it's immediately become a critical and expensive problem to fix. Should the dealer have picked this up through the MOTs and services they did?

Appreciate any advice here!
RC

EDIT: just to address the obvious question, my driving pattern wouldn't impede the DPF from working - the car gets a decent amount of long motorway runs. Even so, only on about 50k miles total, so not huge mileage done.

thescouselander

On my car the DPF automatically regenerates every 150 to 200 miles so on that basis it would probably take a while to hit 400% in normal circumstances.

In your case I'd suspect there is another fault causing increased levels of particulates to be produced. I doubt it's anything to do with the fuel filter - more likely candidates include leaking intake pipework, leaky injectors, a sticking EGR valve or a faulty MAF sensor. Whatever the cause the blocked DPF is probably a symptom rather than the cause so make sure your garage finds the original fault or you'll be back in the same position before you know it.

ratechaser

thescouselander wrote: »

On my car the DPF automatically regenerates every 150 to 200 miles so on that basis it would probably take a while to hit 400% in normal circumstances.

In your case I'd suspect there is another fault causing increased levels of particulates to be produced. I doubt it's anything to do with the fuel filter - more likely candidates include leaking intake pipework, leaky injectors, a sticking EGR valve or a faulty MAF sensor. Whatever the cause the blocked DPF is probably a symptom rather than the cause so make sure your garage finds the original fault or you'll be back in the same position before you know it.

I'm with you in that this looks like there's another root cause somewhere. I'm not entirely daft but unfortunately my mechanical expertise is close to zero so am quickly trying to understand the basics of how this all fits together. Yesterday I couldn't even have told you what DPF stood for. Now I have EGR and MAF to add to my 'look up' list

Every day a school day. Why the hell have I been paying inflated ford prices when it seems like they are just doing what the computer tells them to...

thescouselander

That's the danger - the computer can only tell you if the various sensors and electronic modules are operating outside of normal tolerances. Working out why this might be is another matter especially when things like leaks might not trigger a fault code.

daveyjp

Over time sensors can fail which lead to DPF problems.

Tha happened to a colleague with a BMW 320d. Failed sensor, incorrect readings to control module, killed the DPF.

System

ratechaser wrote: »

EDIT: just to address the obvious question, my driving pattern wouldn't impede the DPF from working - the car gets a decent amount of long motorway runs. Even so, only on about 50k miles total, so not huge mileage done.

The one on my Mondeo is on 128k so yeah if that's your driving pattern something is most definitely not right. Mine did suffer an issue where the rubber pipes from the DPF filter to the DPF pressure sensors got brittle and split due to the heat which both threw up a warning light and prevented the car from doing a regen until it was fixed.

ratechaser

So to ask the obvious question, is it reasonable to expect a ford garage to have the expertise to identify the underlying cause? Or at least proactively get Ford UK involved for an investigation? Because right now it seems like they are just reacting to diagnostic error codes. Fix one error, up comes another one. And so on.

Otherwise I might as well pull it out and go to the Halfords autocentre for a third of the price...

thescouselander

Ford should be the best equipped in theory but there's no guarantee you'll get the right diagnosis - I've had wrong diagnoses from dealers before.

If the dealer can't explain how the DPF came to be blocked it's probably a good indication they haven't found the root cause. It might be a good idea to have a word with the service manager to express your concerns and make sure one of the more experienced mechanics has given everything a good going over.

Noree

Just for info, a DPF can block quite quickly if you dont drive for reasonable periods on the motorway.

The exhaust matter can not be processed correctly with the DPF.

It may be worth checking what oil has been used. Yes it has been going to a Ford dealer, but it has been known that dealers get it wrong with the basics, such as not using Low Ash (LA) oil for anything with a DPF.

If the dealer has used the wrong oil the it is their liability to have not serviced the vehicle within the expected standards.

[Deleted User]

My sister had DPF filter replaced on a 2009 1.6 Focus with 108K miles at a Ford dealer last month for £300.

It had gone into limp home mode, local garages were quoting all sorts of horror stories, yet Ford dealer diagnosed problem straight away.

ratechaser

Deleted_User wrote: »

My sister had DPF filter replaced on a 2009 1.6 Focus with 108K miles at a Ford dealer last month for £300.

It had gone into limp home mode, local garages were quoting all sorts of horror stories, yet Ford dealer diagnosed problem straight away.

Well clearly a Focus DPF must be a bit cheaper than one for an SMax, as my ford garage said it was £1364 just for the part :eek:

Versus halfords that would do it for £640 inc labour... that'll be a hard decision...

But still leaves open the question of how it got that bad so quickly on a fairly low mileage car that does get motorway runs. Let's see if they can figure that one out...