[Closed] DPF regen causes diesel to be not as cheap as you think shocker...

would a 2007 Saab 9-3 1.9TDCi have a DPF?

I used to notice occasionally on the motorway at 70 (when possible!) that the engine would feel lumpy & unresponsive, then after about a mile it would sort itself out. DPF regen? no matter, not my problem now, the Saab got sold in 2011ish

Kryton57, you said you'd notice it in your Kuga, what are the symptoms? just much lower than expected indicated MPG for a while?

BTW 40mpg in an Alfa I'd say is quite respectable! even if it is a diesel 🙂 I had a 146 1.6 with the boxer petrol engine, never got better than 32mpg, then a 156 1.6 T-Spark, which never gave more than 35mpg

Kryton57, you said you'd notice it in your Kuga, what are the symptoms? just much lower than expected indicated MPG for a while?

Its hardly noticable, in fact if I'm talking with my wife or chatting with the kids I'd miss it. The two occasions (ours is used mainly for the school run) I've experienced it I've just felt that the throttle response was ever so slightly muted.

Its much more noticable in the Alfa but then the torque isn't so strong at 1500 Revs in 6th as the Kuga's is.

The DPF in our Golf just failed, it warped! Apparently there was nothing we could have done to prevent the failure. We're still under warranty but the DPF is not covered. Close to a £1200 bill (that's with a dealer contribution as they're feeling guilty)... Not best pleased! Currently arguing the toss with VW.

Is there any way of telling if a car has a DPF or not? I bought a 2007 Passat 2.0 Tdi recently, the DPF was still just an option at that time (I think!). Any way of finding out for sure?

We were all set to go diesel with our latest sensible car. Then went petrol in the end. Fewer nasty emissions, £1500 cheaper than the equiv diesel (which buys a lot of fuel), fewer expensive things to go wrong, does 60 mpg if you drive like a Vicar, 30 mpg if you rag the living shite out of it. I once managed to get it down to 28 mpg by redlining it up and down the box in the lanes, just to see. Modern petrol cars are amazing, if boring.[/smug]

Had mine removed before Christmas .... Glad to see the back of it ...nothing but trouble

My Fiesta regens every couple of weeks or so.

I'm doing 400 - 500 mile a week mainly town stuff with the learners. It bounces all over the shop and the idle is awful when it regens.

Also kicks out loads of grey smoke. Depending on who I'm teaching, I wind them up and tell them they have broke the car 😉

I usually prevent it regening by taking the roofbox off and caning it between lessons, all within legal limits but you get some filthy looks when a learner car accelerates hard away from the lights so it's better to take the roofbox sign off.

Another way is a blast down the motorway every 10 - 14 days. I know its natural for it to regen, but I worry if it did it on test and the examiner thought it was broke.

what's a regen smell like ?

every now & then my car smells of burning rubber, to the point where I go & check the tryes for rubbing. I'd never thought it could be the DPF

?? ❓

*googles, sees it does, relaxes, deletes noob question*

😀

Can't you just get rid of the dpf and get a custom engine remap whilst your at it..

Can't you just get rid of the dpf and get a custom engine remap whilst your at it..

I did

I beleive not having a DPF (on a car that should) is now an MOT failure.

How vigilant the testing centres are on this I don't know

I don't think all dpf dump spare fuel into the sump but apparently my Mazda 6 does. Hence mine was serviced then 3k miles later needed another oil change due to a failed regen. Never mind the cost of mpg, factor in the cost of, essentially, another service and diesel cars seem quite expensive.
It's great to drive and no car is cheap but there are significant hidden costs IMO.

I beleive not having a DPF (on a car that should) is now an MOT failure.

Take the filter off, remove the internal gubbins, weld it back up and put it all back in place.
None the wiser

I beleive not having a DPF (on a car that should) is now an MOT failure.
Take the filter off, remove the internal gubbins, weld it back up and put it all back in place.
None the wiser

Yup, aware of that solution. i interpreted your statement that you'd literally taken rhe DPF off the car, rather than the more sophisticated approach. My mistake 😀

Due to a clogged DPF I am today £1500 worse off.

With a new DPF fitted it's an ideal time to get rid of the diesel car and go back to petrol.

Diesel cars PITA!

D*F two 3 letter acronyms that are making 3l v6 petrol cars seem appealing from a running costs perspective.

Edit on reflection I maybe looking for excuses I miss my 406...

I lurk on two motoring forums. One Honda and one Mercedes.
Only very very occasionally is DPF mentioned on the Merc forum but it has its own folder on the Honda forum. I have had no problems owning a Merc diesel (I've never smelled a regen from mine or I think had one in 26k) but I wouldn't buy a Honda diesel. I use our Honda petrol all the time around town. Not even a blown bulb from the Accord in 5yrs.

This thread is why last week I sold my Mondeo diesel and bought a Kia Soul petrol.

Over the last 5 years, I've put around 170,000 miles on three different diesel engines - no DMF issues, no EGR issues and no DPF issues.

Meh

weeksy - Member
This thread is why last week I sold my Mondeo diesel and bought a Kia Soul petrol.

POSTED 23 MINUTES AGO # REPORT-POST

Time travel!!!!!

You win t3h interwebs 😀

What numbers for tomorrow's draw please? 🙂

Kryton, you need to go and rag the living daylights out of it. Sounds like the previous owner was a 6th gear @ 20mph specialist and it's a bit bunged up. Might need an oil change for good measure.

It's an alfa, drive it like it should be driven and it'll reward you.

It's an alfa, drive it like it should be driven and it'll reward you.

Hooked up to the back of an AA truck?

With my Yeti I ignore the change up Arrow as it's wrong most of the time. I will only cruise in 6th at about 1750 rpm and above. The DPF light hasn't come on once in 3000 miles so far. Much happier in 4th and 5th in and around town. MPG is about the same 42ish, I was getting 30ish out of the VRS pootling about. You still have to drive these cars and not pootle about at low revs looking for every MPG.

Yep my yeti's the same. Wants you to bimble along grinding the arse out of the big ends at 1000rpm. Just sounds and feels so wrong. Dads dsg-equipped Superb is also the same. He's taken to switching it into manual mode and holding the gears a little longer than auto would. No difference in mpg but undoubtably less miserable for the rods and crank.

Chipsngravy what car was that?

Kryton, you need to go and rag the living daylights out of it. Sounds like the previous owner was a 6th gear @ 20mph specialist and it's a bit bunged up. Might need an oil change for good measure.

It's an alfa, drive it like it should be driven and it'll reward you.

Once I have removed the suicide tyres on Monday, I'll give it a few more beans.

This thread is why last week I sold my Mondeo diesel and bought a Kia Soul petrol.

I think the problem here is that the manufacturers fuel consumption figures are ludicrously optimistic. I know there are regulations for how they are reached but they don't reflect in any way how are a car is likely to be driven in real life.
If you're a business user and someone else (customer I suppose) is paying/time is money etc then you won't have DPF issues. If you're a private user and buy a car that has good fuel consumption numbers then there's a good chance you'll try and achieve them. If that car's a newer Diesel with a DPF you'll clog it up.

On a related note, I own a Diesel estate but I really don't do enough miles and, as I'm looking to replace it, I'm considering petrol. If I go on Autotrader and search: £20k to £35k, within 100miles, <20,000miles, automatic & estate I get 597 Diesels, 28 hybrids, 30 petrols & 2 unlisted. Twenty times as many Diesels as petrols 🙁

If I wanted a petrol XC60, it would be a 3ltr turbo and Volvo sold about 10 in the UK. Would cost me over £400 to ved it, rather than £200. And for urban would do about 15mpg. So , for Volvos best selling current vehicle, means that diesel is the only option. We have had diesel cars for the last 8 years for the family car and they chug 4 miles each way to work for the missus, twice a day, as she comes home for lunch and we have yet to face a dpf issue. All of them had DPF's fitted. Later cars have a different form of regen that earlier cars and the materials of the dpf are better than earlier versions. Wifes going to go for a blast for 20 miles shortly, to go shopping, so that's the regen sorted. And its not made us go out of our way to do the regen.

Thrustyjust - Member

This thread is why last week I sold my Mondeo diesel and bought a Kia Soul petrol.

Christ mate, has life got you down that much ??

Not at all, the Kia has 3.5 years warranty, it gets 42mpg average, ok, it's not as nice, nor plush as the Mondeo, but it's fine.

the Mondeo cost me £700 for a cracked coolant hose, the DPF would need replacing in the next 10,000 miles, it needed 2 new tyres and the clutch would last maybe 20,000. All in all, it was a money pit waiting to happen.

I have a GSXR750K7 for speed, I have mountain bikes for fun.. a car is just to take me to work and back each day. The Kia is competent.

I'm DPF wary but since I fancy a T4/5 with minimum 6 seats the petrol options are limited. Open to suggestions tho!
We had a 2005 Scenic 1.9d which did cause us some dpf regen dealer costs until we figures out how to spot it before it became a dealer issue. Wouldn't buy one again for town driving hence we now have a petrol Jazz.

Weeksy, not sure how many miles your Mondeo had, but my mates on 140k so far and has needed a new clutch at 110k. That's it. No signs of dpf issues yet on a 57 plate car. We put a new battery in it last summer, just because. Other than that , it runs like a dream. He pays £60 a tyre at Newbury Tyres near the Police Station and they are 18's as his is a Titty X. I don't think there is an expected life on some things or taxis wouldn't be doing intergalactic mileage in them and I am sure they don't cut out the dpfs. They wouldn't have the intelligence.

This seems as good a place to ask as any; some Diesels look after their DPFs by injecting stuff. Off the top of my head I'm thinking Mercs and some Frenchies. Anyone have any experience of the reliability of DPFs in those??

700quid for a coolant hose..... They nailed your hat on with that ..... Or did you miss it and cook the hg ?

Surely this is evidence the car needs a good blast / blow through on a regular basis 😉

My last Smart CDi didn't have a DPF and averaged 67.2 mpg over 27195 miles.
My current Smart CDi has a DPF and has averaged 65.8 mpg over 28547 miles but the engine has 9 hp more than the last one.
Hardly a massive amount of difference either way.

The best thing is probably to drive quickly but constantly in a too low gear. Ragging it with hard acceleration might not get the exhaust temp up high for long enough, and when you floor it it might make more smoke and make matters worse.

This seems as good a place to ask as any; some Diesels look after their DPFs by injecting stuff. Off the top of my head I'm thinking Mercs and some Frenchies. Anyone have any experience of the reliability of DPFs in those??

It depends what stuff you're on about.
PSA engines use EOLYS fluid, which is injected into the diesel tank everytime you refuel. It's a mix of chemicals which helps to lower the required temperature to carry out a regen.
I say PSA, because fords with 1.4/16s use PSA engines, and also have the doping system.

I can't say there's much difference in reliability. DPF issues can be pretty much narrowed down to two main causes. Vehicle use isn't suited to DPF regen i.e. lots of short journeys where things never get hot enough for regens, or a base engine fault, which means too much soot is being produced and the DPF is being loaded too quickly.

Newer Merc/VWs are now also using Adblue injection and catalyst systems (commercial vehicles have only had to start using DPFs since Euro6/late 2014, as they mostly relied on Adblue injection/catalysts to meet emission limits). Adblue is an additional catalyst system, which helps to further cut various gas emissions, but you still need the DPF to handle the particulates.
I've not had anything to do with the car systems yet, but certainly every truck manufacturer has had issues with their Adblue systems.

Certainly, given the amount of technology that is now required for a diesel to meet emission levels, the economies of them in cars is quickly diminishing. A couple thousand pound of extra tech on a new truck, with the occasional thousand pound bill is relatively little in the grand scheme of running costs, whereas on a car it is a major cost.

The best thing is probably to drive quickly but constantly in a too low gear. Ragging it with hard acceleration might not get the exhaust temp up high for long enough, and when you floor it it might make more smoke and make matters worse.

Regen processes do vary quite a bit, but a good drive keeping the engine under reasonable load and aim for maintaining above 2000rpm will generally keep the regen process happy.

Mc, VW have been using selective catalytic reduction on their US market diesels for a while. Apparently you don't need EGR, and I'd read that there were fewer particulates produced.

The reason SCR could meet emission levels without EGR, is the SCR handles NOx emissions. The sole purpose of EGR is to reduce combustion temperature to reduce NOx creation at source, but the downside of that is you increase soot/particulates, which you then need a DPF to handle.

Most commercial vehicles opted for SCR due to fuel economy. At the time Euro 4/5 were reaching production, IIRC EGR systems resulted in a 8-10% hit in fuel economy, which when you're dealing with vehicles doing single digit miles per gallon, is a major cost.
However a couple commercial manufacturers did use an EGR system combined with a conventional diesel catalyst, and sold it on the basis you didn't have any adblue systems to deal with skipping over the fuel economy issues.

For cars/vans, the EGR fuel economy hit was a far cheaper option than adding a SCR system, and some vans avoided DPFs up until Euro5, as there was no legal requirement or tax benefit.
The reason alot of cars had DPFs was to meet the tighter tax levels, not because they needed it to meet the Euro emission levels.

Now Euro 6 is here, commerical vehicles need a mix of all systems, and car/van manufacturers are having to chose between expensive systems and fuel economy.