OT: Diesel particulate filters

I bought a car the other week with a 2.0TDI, i'd read the horror stories about modern diesels but felt that our mix of driving would suit it, fair enough it's normally short journeys during the day but a decent (20 mile

+) jaunt at least once per week.

After having it less than a week the DPF light came on, the next couple of moderate journeys didn't regen it and it went into limp mode and ended up garaged.

A week later (today) the DPF light came on again so I stuck it on the motorway and drove at approx 2500RPM until it went out, took approx 25 mins.

Are they normally this much of a PIA?

Reply to
R D S
Loading thread data ...

No, they are often much worse.

Reply to
Peter Parry

I have a Kia and and never had a problem, even when I don't manage a long run for periods so I'd say your experience is worse than average.

That said, since the advent of DPFs, diesels are now a poor choice unless you do a decent mileage and I won't be buying another, particularly now that small turbo petrol engines have improved so much.

Tim

Reply to
Tim+

Not IME, though mine probably gets between6 to 10 one-hour motorway journeys a week so unlikely to, occasionally I do catch it out, let's say it's been waiting to do re-gen, I go out for a short journey, it gets the wrong idea when I stick my foot down on the by-pass about a mile from home, and it starts a re-gen ... by the time it's got itself up to "furnace" temperature, I pull up at home and stop, the car then sits there will all fans on max for 1/4 of an hour cooling itself down again, but it just tries again next time I go out.

Maybe the previous owner was a town driver only, and the first regen didn't really clear it?

Is it a VW/Audi/Seat/Skoda? If so drop by the VWAF forum, they have a register of people on a map who have an ODBII cable and the VCDS software that can read diag info from the car including the ash load in the DPF, could be someone local to you willing to give your car a scan for the price of a pint ...

Reply to
Andy Burns

That, I'm afraid, is modern life. As dictated by our Eurolords et al. Diesel is inherently good. Modern legislation makes it far less so. Does your car have an EGR valve? These can cause probs but can usually be effectively diy cleaned. Short trips can play havoc with all this gimmickry. A sustained run, as you have found, will normally do the trick. Better still is more & longer journeys. It is also worth considering changing where you buy your fuel. Supermarkets are cheap for a reason and it's not because they love you.

You might consider resending your post to uk.rec.cars.maintenance. Still going and some knowledgeable folk there. I've run Toyota diesels for more than 25 years. None has ever been any problem, except the newest.

I hate and detest acronyms but, sadly, they are also a fact of modern life !

Good luck, Nick.

Reply to
Nick

One of my lads had terrible problems with a Pug, I think it might have been a 307. This was one of the things which had a little tank of "stuff" to help clear the filter which gets injected every time you remove the fuel filler cap. Because he was a bit pressed for cash he only ever put in a couple of gallons of diesel at a time, so ended up using up expensive stuff five times faster than he needed to. And it didn't stop him having a string of problems with the engine management system or MOTs. On the advice of my mechanic, the main car is on an 04 plate, one of the last Astras before common rail came in. Both economical and trouble-free. As one of the other posters said, petrol for me next time, I think.

Reply to
newshound

Um, how so? City centre air quality has declined in line with the growth in the sale of diesel engined cars. The "official" emissions tests on rolling roads are thought to be very poor at predicting "real world" emissions from diesels.

Well, they are improving the emissions a bit but clearly the technology is lagging behind the legislation.

Or sell the diesel and buy a petrol engined car. Economy has improved greatly in the last few years.

Tim

Reply to
Tim+

Not to forget that there are several EU countries where diesels are very much ignored, and bio-ethanol is the preferred bunny-hug fuel.

Reply to
Adrian

EOLYS by any chance?

Because he was a bit pressed for cash he

The problem with EOLYS is that it is a very hazardous material so you can't go out and buy it and top up your car with it, it has to go to a Peugeot Garage for them to top up the EOLYS for you......

Thats progress eh?

Reply to
Stephen

Never had a problem with either a VW Touran or a MINI - both diesel.

SWMBO's MINI dies get a good 30 belt up the A21 once a week - mine is completely random - perhaps once a month it gets a good thrash along a bit of the M25 - otheriwse just millions of small journeys.

Reply to
Tim Watts

In message , Tim+ writes

My question is whether modern petrol engines doing start, long stop, start, stop and so on are any better than my old petrol cars. These, when life dictated that sort of use, were on full choke or full injection all the time and did horrendous mpg's.

My pre DPF diesel, as I've said before, took me from the petrol 7or 9 mpg to about 40.

I suspect that what I really need is a diesel hybrid with a small, cheap to replace battery. I don't think there are many of these in my secondhand price range, especially ones like my old Mk1 Cortina estate that would take an 8 x 4 sheet of ply in the back.

Reply to
Bill

Second hand? How old? You're suffering with the previous owner's usage pattern and understanding of the system which probably meant it rarely regerated.

Owning one requires everything to be just so:

  • Car must have at least a quarter of a tank of fuel - so throwing a tenner in is bad.
  • The coolant must be *preoperly* up to temp - so short journeys bad and, more importantly, lazy thermostats can completely bugger it up. Many BM owners have extracted the coolant temp via OBD and found it at
70-odd C when it needs to be 80-odd+.

  • DPF filter must be hot enough but not *too hot*. In some cases a good "this'll get it hot" thrash gets the exhaust temp too high for the ECU to consider lobbing in the extra fuel for DPF heating.

  • Many "aware" people have found the regeneration kicks off just as they arrive somewhere and they then go for another 10 mile jaunt to make sure the process runs through. For each of them they'll be 100 that don't have a clue so shut the engine off and, natch, no regeneration.

Bloody stupid things really. How burning extra fuel (or forcing people to drive further) is particularly eco, I don't know. To my mind the best solution is to be aware of how to get the thing to regerate properly and, when it eventually goes down the tubes, get the DPF innards removed and it mapped out of the ECU. Technically DPFs are part of the MoT (must be present) but the word on the street from the MoT testers is that they're prosaic enough to ignore a gutted one as long as the canister is still there and, if cut open and welded, it isn't blatantly obvious.

Mind you, I was reading about AdBlue the other day. Better idea, you have a gallon of urea (yes) in a tank which doses the emissions up for

10,000 miles. However, if the tank runs empty the car Will Not Start. Yay.
Reply to
Scott M

I haven't had any problems with mine since, fortunately, my usage patter is very low local mileage with occasional longer runs, which seems to work OK.

For those of us ignorant of the finer points, how would I be aware of regeneration being initiated?

Chris

Reply to
Chris J Dixon

  • Change of engine note (injection timing is changed to raise EGT and then fuel is injected on the exhaust stroke to burn on the DPF.)
  • Autoboxes will hold lower gears to amplify the amount of fuel use above (also makes them a better bet for getting DPFs regenerating really.)
  • The exhaust will sound and smell "hotter" (which ain't a lot of use until you clamber out!!)

It's all pretty subtle which doesn't help. Why they don't just put a light on the dash saying "Currently Regenerating - Keep Going!" I don't know!

Reply to
Scott M

There is this new fangled thing called the internet that helps in these circumstances

Reply to
A right charlie

The combination of which give you a spell of noticeably lower MPG, I tend to leave an average+instant MPG display on the trip computer when I'm not* in a built-up area, so sometimes spot it that way.

[*] when I am, I tend to switch to a digital speedo on the display.
Reply to
Andy Burns

On many of my long runs, I can get home with a greater "miles remaining" than when I started.

Chris

Reply to
Chris J Dixon

Or maybe if you have a smart phone (android?) you could download the Torque App and buy a OBDII bluetooth adapter for under 10 quid

formatting link
(there is a free version)

formatting link

Reply to
alan

Find a local tuning shop that will "tune" it..... i.e. cut a hole in the box, mash the dpf innards into bits, tip it all out and weld it back up again. Followed by a "DPF Delete" and an "EGR delete" re-map which, while your at it get a tuned re-map.

Might cost you a few hundred quid but the cost of a replacement DPF is WAY more as is the cost of replacing a w4nkered turbo charger due to a blocked DPF...

Yes it will still pass the MOT as it only has to be evident if fitted from manufacture, not "effective" AND I believe you'll find stopping the EGR from screwing up combustion efficiency actually reduces exhaust particulate emissions (which is tested) at the expense of increased NOX emissions which isn't tested.

That'd be my tip rather than waste the same amount (or more) on replacing the DPF which will only block again in time.

;¬)

Pete@

Reply to
www.GymRatZ.co.uk

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.