mcst

We're looking at a diesel with a dpf fitted. General opinions are that unless you are doing high mileage they are bad news.
Is this just internet scaremongering? Are they that bad to live with?

It appears that most people have issues when they ignore the light and it doesn't regenerate itself, usually as a result of short journeys.
I remember all the fuss about Cats when they were introduced and nobody even gives them a second thought now.
I know some cars have newer systems and also that now they've been out for a few years there are aftermarket firms offering cheaper fixes than main stealers.
We will probably do a maximum of 15k a year but will realistically be about 12.5k and can easily adjust our driving to accomodate ie taking in a high speed blast every few hundred miles.
The car we are looking at doesn't come without a dpf on the diesel and the petrol is a no go. I don't want to get stuck with something that needs a forced regeneration all the time and the savings are negated by the service costs.

Chip

iTrader: (3)

I wouldnt want a modern diesel car with a DPF if I could avoid it, especially not for short journeys, it does nothing that benefits you, and is a potential big expense.

If you do as you say and open it up properly every few hundred miles though you *should* be ok.

Bailes1992

I'm getting a Diesel next, 406 HDi to be precise and although I can afford the 2.2 136 HDi I'm doing for the lesser 2.0 HDi 110 simply because the DPF and ELOYS tank. They can be removed fairly easily but I don't want to have to have the hassle.
They are fine on the motorway but start/stop journeys and they get clogged up.

mcst

But do you have direct experience of the issues or are you just going by the internet moaning. I've read the same but there must be 1000's of happy customers using them normally without an issue. Reading between the lines i think people are using them as normal and when the light comes on not following the advice to take it on a run to increase exhaust temps, it then becomes further blocked resulting in a need to take it to the dealer.

Sales staff are supposed to advise that they aren't suitable for short journeys but it appears harder to buy a diesel without a dpf now. They're obviously not going away and as they progress they are improving the regeneration cycle.

Whats the alternative if you want a diesel? The car we want isn't available without a dpf and the petrol is a no go.

Chip

iTrader: (3)

I personally know of people with diesel engines who have had problems.

Talk to any diesel remapper and you'll find its one of the very common things we get asked to do (DPF delete)

vroooom ptssssh

Easy enough to delete, just an expense...i've re-generated some DPF's that have been blocked solid which worked but for the time and effort you're as well deleting it!

As chip sais for people who do mostly short journeys and don't really give the car a boot often then it's probably something you should consider hard or avoid!

Fil

My navara has a DPF Never knew about them , until i bought it and the light came on!

wouldn't buy another car with one fitted, 1st off the year before without it, has 5bhp more, and returns 4-6 mpg more! Envirnomently useless crap!


Yes my light came on a few times, Sposed to take it on a run, not possible when your sitting in traffic and it comes on!

Cleared it a few times, tho it uses up some fuel! Just what you dont need

|Then it came on one day, with in 2 miles went in to a limp mode, that only a dealer can reset they force re-gen'd it and then requires an oil change ( special expensive dpf oil required! )


Dont here people who do long runs having issues, but 95% of my driving , short ( 8 miles to work ) and in traffic , east london

I will get it removed and the ECU sorted one day, then possibley ram it up the Cunts arse who came up with it!

Fil

Just to add, when i removed the DPF to clean it out myself ( didnt work btw )

It had tipex'd on it "navara auto 08 Ł150" mines an 07, so not even the original one fitted only done 72k

Chip

iTrader: (3)

Not all cars cope well with them removed, and even people like evolution chips dont have ALL models covered yet, although they have a fairly extensive range.

Its certainly something becoming more and more of an issue.

gus

iTrader: (1)

do they need to be refitted for mot?

i will be buying new so wont need an mot for few years but knowing me, i will probably skip it

Chip

iTrader: (3)

No, not normally a problem for MOT at all.

Its daft with diesels that they have to have all this junk attached for type approval in the first place, but then no laws to keep it on there.

Great news for people in the business of removing them though, lol

gus

iTrader: (1)

is just a case of unbolting and replacing with straight thro or is there mapping needed to compensate

wanna get the car remapped anyhow

would there be warrenty problems

Chip

iTrader: (3)

Depends on the car Gus.

Broadly speaking though most cars if you remove the DPF, it will be seen by the ECU as an error as the sensors monitoring it will now be out of range, and you'll end up in limp mode.

With regards to warranty, if you are still in warranty then surely you just take the car back and insist THEY fit a new DPF anyway so no need to delete?

gus

iTrader: (1)

would be for a zetec s fiesta

when pops went to buy his insignia that told him the dpf is not covered as he has been instructed on how to maintain it

i meant if other issues arise with dpf missing
putting it back on before taking back to fords might not always be possible

Chip

iTrader: (3)

Putting back on almost certainly not possible for most people as the normal way they remove it is to take the DPF off and smash the innards out of it. Lol

Thats interesting about the warranty, but they would have PROVE you didnt maintain it appropriately to not pay out surely?

gus

iTrader: (1)

o i thought you would just buy a decat kinda of thing

Fil

Theres a few replacemernt pipes about for some vehicles, but seem very expensive for what they are.


Not the hardest of things to make, just the ecu side of things thats not diy

TIFF

Just remove them and get it mapped out.....DONE...

mcst

Some worthwhile info, thanks all. All you can find on the net is people just saying they're shit - without any evidence to support why - i understand the issues with them but as i said earlier in a lot of cases people haven't taken the appropriate action. My mrs will be commuting in it, the mornings she doesn't hit traffic at the time she goes in, coming home she hits traffic couple of times. I can't see if she drives it as hard as her ST170 and uses a lower gear to work it a bit more in the nsl areas, it being too much of a problem to us. We would be using it more than the focus anyway as in all honesty the cost of running it puts us off some journeys such as her going to see her mum and sister which is mostly nsl roads a good 40-50minutes away, she can take in some motorway without it taking her out of the way too.

I'd already considered a remap too so i can look to delete the dpf if it becomes an issue for us.
I've already read that the warranty doesn't cover it now. It appears in the early days dealers were doing a regeneration under warranty. Now when sold new they are having to advise people that if you do frequent short journeys from cold its not for you. I believe it does depend on manufacturer too.

Chip

iTrader: (3)

Bare in mind if you get a remap done with a DPF delete, that you MUST remove the DPF at the same time.

You cant get the DPF delete done, and then keep driving it around with the DPF in place, as if you do so then the DPF will fill up in no time at all as it wont be getting purged ever, and when it does fill up because the ECU is no longer monitoring it, it wont go into limp mode, it will just try and carry on regardless.
This will lead to a higher amount of exhaust back pressure between the turbo and the DPF, which means that for the turbo to spin it will need to have a much high back pressure between the turbo and the cylinder head (ie it will stop any gas going down the wastegate as it will need it all to still try and spool)
This much higher back pressure will lead to drastically increased EGT's which will in turn then kill either the engine or the turbo, or possibly both.

Im sure the thread starter realises this as he seems quite clued up on the subject, but just mentioning it for the benefit of others who might read it and not realise.

Its not uncommon for people to ask for a DPF delete on the software for a future proofing measure when having a remap even though they have no DPF issues yet, but if you dont at the same time remove the DPF, you will soon regret it.

mcst

I've seen that some people have ignored the light and its gone into limp mode and the things blocked up causing a whole load of issues as you describe. Even if i don't have issues i will still look to go through the process of removing it so we don't need to worry about any future problems.

matts1

my mates old lady has bought a vauxhall with one, its a pain in the arse for her. She does short journeys and is a timid driver, she ends up having to go for a long run at a certain speed.

She hates it as she is a 30mph tootler of 60 years old.

botters

iTrader: (2)

ive had loads of problems on cars with dpf's fitted on customers cars they are a pain in the arse, it is far cheaper to get the dpf delete and remap done if possible than sorting the problem
also when they are in regeneration mode they sup fuel like fuck
waste of time in my opinion, ive removed them and checked the emmisions afterwards and many times seen lower emissions with them removed!! allthough usually they are slightly higher but never anywhere near enough to fail an mot

JamesH

iTrader: (21)

Done this on development before, it just suffocated the engine in the end and it wouldn't run

Avoid DPF's even if just from a fuel economy/oil dilution point of view

Jeffers_RST

Simple answer which a lot of people have actually said is infact YES they are an overpriced wasted of space. They dont actually do anything for the environment, they may filter the diesel shit initially but come to a regeneration and it'll chuck it all back out in one big go! work that out! I can only speak for Mercs being a truck and van mechanic for them, but not only are they over Ł1200 to replace when they go wrong depending on the vehicle, but you have to use low ash oil which i think is about Ł20 per litre to stop the dpf blocking up. ive driven a van which actually broke down when the dpf completely blocked up and wouldnt run for more than 3 seconds!
Just remove it when it goes wrong, get the dpf settings deleted and itll pass an mot no problems! trying to avoid them is near on impossible with new diesels cos most of them have got the fu*kin things!
Cheers, Neil

Bailes1992

Has anyone thought about running two stroke oil with the diesel help diesel these DPFs along?

I used to run 250ml to a full tank in my last 406 and it stopped any smoke there was (very minimal anyway), got better MPG, better cold starting and much better throttle response/pick up Make sure it's low ash obviosuly

markk

iTrader: (2)

a lot of problems people are seeing is simply beacuse the old diesel engines are very dirty.
The manufacturers saw it as a way to clean up the already in production engines to meet euro 5 compliancy.
a few years later and most manufacturers have developed new diesel engines and DPF issues are now becoming less and less.

If you are not working with a manufacturer then you will be seeing the problems the manufacturers has 3-5 years ago. nowadays the engines are super clean compared to a few year ago, we even have DPF cars in driving schools, I have no problem with new generation DPF vehicles.

Chip

iTrader: (3)

Yes the modern ones are getting better in terms of the engine itself (massive rail pressure behind the injectors to atomise it better) in terms of the ecu controlling the dpf burn off, and in terms of the DPF themselves.

The problem is with the earlier cars where the technology was very much an add on to existing engines not an intergrated part of designing the engine in the first place.