Diesel Particulate Filter

Engine, Exhaust, Drivetrain, ECU
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Muddles
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Diesel Particulate Filter

Post by Muddles » Wed Jun 21, 2017 11:50 am

I've been pondering a while whether to trade my Cactus in for a petrol version.

The thing I'm concerned about is the DPF. I've never had problems with one before, but these days I do very low mileage. Hardly 50 miles a week. But living in Cornwall, just a trip to the shops is over 10 miles and dual carriageway (the main A30) where you can get your toe down.

I've been scouring the auto tech sites and reading as much as I can about the DPF's, and still not much the wiser.

I found a Citroen owners page that informs you the type of DPF they fit, but nothing helpful like are they passive or active when they regenerate. It just stated they use carbon coated filters and the Adblu system.

http://www.citroen.co.uk/owner-services ... ate-filter

I've also discovered that when the warning light comes on to let you know the filter is 75% full, then you need to drive the car over 40mph for half an hour so the filter can regenerate and burn off the soot. I also discovered Citroen Peugeot and Ford systems do not need to reach such high temperatures as other makes when regenerating.

The only advice I found was that diesel cars are fine for people who do a lot of short trips as long as they go for a half hour drive over 40mph once a month to allow the filter to regenerate. But should not be considered for city driving or a lot of stop start driving. If the system regenerates on its own timetable that may not be when you decide to go for a burn up on a motorway. So you think you're doing right when in fact it's not helping at all.

However, if your engine begins a regeneration and you interrupt it by either being held up in traffic, or you reach your destination there is no info regarding whether or not the engine will carry out another attempt on the next trip, or whether it will wait for another 250-300 miles to do one, as some advice says it is only done at those distances. In which case your filter could become blocked if you had to wait another 250 miles for the next regeneration, say.

There is some technical information about the different types of DPF's but nothing specific for particular makes of car. Nor is there any warning light to make owners aware their engine is carrying out a regeneration, so they can ensure they continue driving over 40mph until it has completed, which can take between 10 - 30 mins. There is only the light to tell owners the filter is blocked.

Here's the technical info I found about DPF's in general, which is very interesting.

https://www.honestjohn.co.uk/faq/diesel ... e-filters/

Another puzzling thing is, should the DPF become so blocked the car won't run, there is conflicting advice, some say the filters can be flushed through and cleaned, some say the dealers can carry out an emergency clean, and some say the filter has to be replaced. Unblocking a DPF seems to cost around £100 give or take £20.

And lastly, once the filter is blocked and cannot be regenerated, and it has to be replaced, prices are bandied around willy nilly from £800 to £3,000 depending on the vehicle.

DPFs are designed to need replacing every 80,000 to 100,000 miles, but for anyone who just does short trips and never goes for a 30 minute continuous drive at 40mph the filter may need replacing sooner.

If anyone else can throw anymore light on this that would be very useful.

So do I keep my diesel Cactus or do I trade in for a petrol. I'm retired so whatever I do and whichever car I keep/get will be my last. Money is a factor, I don't want to be paying a huge a amount every month for years as I'm not that rich, and at 64 I'm not old but I'm at the age when every day is a bonus and I could be gone in 5-10yrs. Anyone my age probably understands that more than the younger members lol

Which brings me round to the fact I love my diesel Cactus, and he is everything I want in a car and maybe if the DPF did need replacing it would be a lot cheaper than getting another car.
Last edited by Muddles on Wed Jun 21, 2017 3:41 pm, edited 1 time in total.
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The2ems
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Re: Diesel Particulate Filter

Post by The2ems » Wed Jun 21, 2017 1:51 pm

I know someone who had a diesel qashqai and only did low mileage. It cost her over £1000 when it broke down.
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Muddles
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Re: Diesel Particulate Filter

Post by Muddles » Wed Jun 21, 2017 2:01 pm

Nissans are known for that.

I've had 2 Fiats both low mileage no problem at all

Hardly worth getting into more debt to exchange my diesel for a petrol. I think it's worth risking keeping it and if the dpf needs replacing at least it's cheaper than having more finance hanging around.

This is the way I'm thinking at the moment, although that could all change tomoro lol
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ZLUsurfer
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Re: Diesel Particulate Filter

Post by ZLUsurfer » Wed Jun 21, 2017 7:51 pm

Hi there.

You can tell when the DPF is having a regen cycle by using the trip computer. Mine does it approx every 600 to 800 miles (or every other tankful). I do the same 19 mile trip each way 5 days a week at steady 60mph with Cruze on. Generally shows between 74 to 85mpg (sometimes up to 91 mpg if tail wind & slipsteaming a Lorry) on each individual zero'd trip (except this week dropped to 68-70mpg due to aircon use).
When it has a regen, the individual trip will drop like a stone to low/mid 50's mpg (without aircon being used or a headwind) - also engine does sound slightly coarser & the stop start system will not stop the engine until regen has finished. The regen usually starts approx half way and complete at end of 19 mile trip...
Had a Berlingo 90hp hdi normal DPF (not Adblu) 2014 prior to my diesel cactus blue 100hp, and that used to do regen every 200-400 miles...and was doing even more regular than that before I swapped for cactus.
Took a gamble having a cactus diesel because of this & are much happier with less frequent regents. Think you should be ok with yours, as long as you take it for a decent trip once every tankful/every month.
Not worth px for petrol as cost to swap could wipe out any possible money being spent IF it blocked.
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Muddles
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Re: Diesel Particulate Filter

Post by Muddles » Thu Jun 22, 2017 1:57 am

Thanks for that, you've been very helpful.

So the system knows when you go for a longer drive and kicks in to regenerate ? I wondered if it had its own set time and worried incase I took it for a long drive so it could regenerate but it wouldn't as it wasn't it's set time to do it, if that makes sense lol

Thanks again for your help.

Yes I'd stand to lose a lot of money if I traded in for a petrol.
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FrankBullitt
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Re: Diesel Particulate Filter

Post by FrankBullitt » Thu Jun 22, 2017 2:38 pm

As has been said you can tell when it is doing a regen as the economy drops like a stone - it is possible to fit an LED to the drivers door mirror to say when it's operating (the DPF regen 'loads' up the cars electrical systems so the heated mirrors and rear window are activated although the heated rear window button doesn't illuminate). If you stop the car in the middle of a regen it will try to do it again at the first available opportunity rather than wait.

As for replacing or cleaning, most manufacturers will tell you they need replacing but they only need jetting which you can get away with once or twice before it becomes impossible to do again without causing damage.

My personal view is don't worry about it, we've had DPF's in Citroën's without an issue despite the car being used for loads of short trips with a once weekly or fortnightly longer trip (sometimes 15 miles each way).

There are lots of DPF horror stories but they tend to relate to VW Audi products in magazine 'owner' reviews as VAG have a habit of sending remapped cars with more power or Nissan/ Renault as the earlier 1.5dCi models suffered.

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Re: Diesel Particulate Filter

Post by Ffrs1444 » Fri Jun 01, 2018 7:37 pm

think im correct to say there are 2 types of diesel cactus the new one has add blue and the older one which we have 15 plate has a additive which get pumped into the fuel system to stop the dpf clogging you just have to rev over 2000rpm.

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Muddles
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Re: Diesel Particulate Filter

Post by Muddles » Tue Jun 05, 2018 11:58 pm

My 2015 BlueHD had the Adblu system, I've not heard of the other type you mention.
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Re: Diesel Particulate Filter

Post by blackcountrycactus » Wed Jun 06, 2018 7:58 am

Nothing can be as bad as the Vauxhall 1.9 cdti(150)for dpf/egr problems , we had one, we found a product well respected in the motor trade called JML DPF CLEANER( local motor factor or amazon ) ,not cheap but could be an idea for you to use.
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Ffrs1444
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Re: Diesel Particulate Filter

Post by Ffrs1444 » Wed Jun 06, 2018 3:13 pm

Muddles wrote:
Tue Jun 05, 2018 11:58 pm
My 2015 BlueHD had the Adblu system, I've not heard of the other type you mention.
this stuff even the dealer said ours had adblue which i thought be cool get it from work when i got home no add blue
https://www.ebay.co.uk/itm/Genuine-Citr ... SwPhdVOflo

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