Viewing 40 posts - 1 through 40 (of 40 total)
  • Car question. Dpf removal….. Anyone had it done and any probs caused?
  • doctornickriviera
    Free Member

    As it says above. I think the dpf on my mazda 6 with 84 k on the clock is ****! Researching on the net states it is a common and expensive failure. Some companies offer dpf removal …. Any thoughts or experiences?

    tonyg2003
    Full Member

    On the Honda Accord formum there are some people that have done this and not had a problem. As long as you keep your car in good shape and you don’t get extra smoke I don’t see a problem. A poorly running car because of a dodgy DPF is probably more polluting (excluding particulates). My ’08 diesel hasn’t got them (one of the reasons why I bought it!) and it doesn’t smoke.

    Have you tried cleaning out the DPF with a jet wash. Apparently this is a fix?

    rickmeister
    Full Member

    Had the dpf removed on my T5 van. Also mapped and the egr valve turned off at the same time. Done 50K miles since, faultlessly. Its good to be free of this expensive and troublesome system if nothing else but performance is improved.

    Pendle Performance, Barnoldswick (next to the Hope Factory)

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    supertacky
    Free Member

    Its a lucrative scam brought on by european environment legistlation.
    As you can tell I’ve been round this loop already.
    My Ford focus TDCi 2.0 was constantly jumping into limp mode becasue of a DPF balance problem. After countless regens – which i can only descirbe as mechanical torture of you engine I decided to bite the bullet and replace the DPF. Another, £250 + engine managment reset and it worked for about two weeks before tripping the limp mode again.
    Eventually, Logic hit me like a silver bullet between the eyes and I replaced the malfunctioning sensor that was repsorting a pressure differental wrongly. £85 and 10 mins later – END of problem.

    Removing your DPF can be done, But its a complex operation.

    supertacky
    Free Member

    BTW my next move was to go for a remap.

    Which as a bonus allows you to smash the sh*t out of the internals of your DPF.

    Milltek – are very reliable and Will talk you through the whole process.

    weeksy
    Full Member

    All of this is why i recently bought a petrol instead of the diesel version. The risks and potential disaster far outwiegh the overall savings on fuel.

    molgrips
    Free Member

    Why do you think it’s ****?

    Did you pay attention to it when driving?

    Have you tried the suggested thorough thrashing?

    DPFs should not be a problem if you look after them, and don’t buy Ford.

    M6TTF
    Free Member

    Dpf causes quite a few issues within the vag range too. Lots of people ditching it on the vw and seat forums. Just depends on your driving style and distances

    doctornickriviera
    Free Member

    Had no end of probs since about 60k. Replaced mass air filter 12k ago + dpf clean, had diagnostics run 3/7 ago by an independent guy and reckons its dead, leaking and probably fallen to bits internally going into mazda tomorrow and if needs replacement may look at removal as an option.

    bigm10
    Free Member

    hi there , iv got a mazda 6 diesel 56 plate , my dpf light came on last year , checked my oil level and it was way above the max level but there is also a x marked on the dipstick further up and mine was above that . took mine to a independant mazda dealer he did a regeneration clean. reset the light job done. keep an eye on your oil level, as if you do only short journeys it clogs up the dpf filter which causes unburnt diesel to be dumped into your oil sump , if you look on your dip stick you have min and max then further up is a x mark , make sure you change your oil before it gets to this point as it can blow your engine. dont worry about your oil level rising its doing its job , taking your car out for a spin 45min or more once a week helps stop it rising to much , thrashing it dont help its getting the car up to working temp that helps burm the filters clean ,make sure you use fully synthetic oil aswell, hope this helps 🙂

    doctornickriviera
    Free Member

    Thanks but done all that and drive 70 miles a day! See what the dealer says! Who was your independent mazda dealer btw ?

    molgrips
    Free Member

    Just depends on your driving style and distances

    That’s what I am saying. You can’t just drive however you want and expect it to work – you have to bear it in mind, which may mean changing your driving.

    Thrashing it does help clean out the dpf, cos it makes the exhaust gas temperature a lot higher burning off any soot in there, and also elsewhere in the engine.

    supertacky
    Free Member

    Molegrips – Its not a problem solely with Ford. VAG, GM Mercedes etc all have the same issues.
    Euro iv immisions forced manufacturers to hastely develope a system that cleaned the exhaust emmisions of their already in production engines.
    Removal of the whole DPF system is very complicated as it has elements based in all sections of the car – The physical DPF is the least of your worries. There are additive tanks that need to be deleted, regen cycles that need to be fooled, differential pressure sensors that need to be mapped out.
    I wont be buying another Diesel until they have developed an engine that doesnt need this complicated and expensive system. Petrol all the way.
    Initial savings of a diesel are wiped out after taking into account servicing requirments of these DPF systems.

    molgrips
    Free Member

    I think Ford are the worst. The different manufacturers use different regeneration strategies. I think it’s Ford where you have to refill the additive to keep it working, and apparently plenty of people don’t even know this and ignore it. VAG and I think PSA don’t use an additive.

    I didn’t think there were any servicing requirements of VAG DPFs (just the possibility of failure). Anyone got any facts on this?

    rickmeister
    Full Member

    T5 dpf removal is pretty simple.

    1. Software, re programme to turn it off.
    2. Replace dpf with a suitable pipe, or remove dpf innards and replace.

    o additive tanks to worry about.

    Think thats it.

    ElShalimo
    Full Member

    DPF jetwashing doesn’t fix them neither does putting additives in your engine. The best way to clean them is to be cooked in an oven at stupid high temps for 6 hrs. See this. The DPFs are made from precious metals like a Catalytic converter, so they can cope in the heat.

    drNick – email me and I’ll let you know what I did with my 6. I did not replace the £2k part like Mazda suggested

    rickmeister
    Full Member

    thats the bitter sweet irony with the dpf… if its blocked, thrash the car up the motorway, use more fuel
    bake in teh oven for 6 hours… labour to remove it, energy to bake it, put it back on etc etc…
    Just a regeneration on the car injects more fuel in to get the temperature up to burn the soot out…

    Its a bit of a flawed system unless the vehicle is driven in a particular way…

    ElShalimo
    Full Member

    vehicles with DPF have to be driven reasonably hard otherwise the exhaust doesn’t get hot enough to turn the particulate matter into soot. (it can depend on DPF lcoation and distance to engine)
    some tips
    -don’t drive around town too much
    -don’t use 6th gear unless you’re cruising at “normal” m-way speeds
    -keep the revs over a certain amount (depends on engine)

    these engines are for designed for motorway miles at those sorts of speeds. If you don’t do that kind of driving then owning a modern diesel is pointless and you’re more likely to have a DPF problem.

    A common theme is that the dealers don’t know what to do with them as its still new technology to them too. They just tend to do what the laptop tells them to do and moan that just cos DPFs work on Californian tractors the EU adopted them. BUT if you want to drive a 2ton car at 85mph and get 45mpg with low emissions then we need them. Its all madness

    supertacky
    Free Member

    Yeah your right Molgrips Renault, Ford, Volvo, Mazda all have DPF additive tanks which inject a catalyst into the diesel tank each time you fill up. Good for about 250 shots IIRC. Once empty the DPF in the exhaust struggles because its not close enough to the engine to heat up quickly.

    The additive tanks are usually on cars that have separate DPF/Cat’s as exhaust temp never reaches burn off in normal use.

    The adative oil is very very expensive and ironicly cancergenic! Refilling is done by a closed loop system and still requires as EMS reset adding to overall costs.

    Audi are by far the worst in terms of expence that I have experience of.

    As i said its a work around to meet euro IV emmisions laws and will in the future be designed out.

    ElShalimo
    Full Member

    has anyone had a DPF removed and passed the emission test on the MOT ??

    supertacky
    Free Member

    As with any problem on cars start fault finding on the cheapest and most exposed parts first before jumping into spending fortunes on major part renewals.
    Most dealers will just replace the most expensive thing and work down from there.

    SprocketJockey
    Free Member

    We had the DPF fail on our Octavia at about 75K about a month after buying it. Replaced under warranty thankfully…. the exhaust pressure valve has also failed recently, but we got a roadside fix for that from Skoda assist. About £50 for the part – I now wonder whether that was the problem in the first place and perhaps the original DPF was actually OK. I’d recommend checking that out before doing anything drastic.

    Thrashing it does help clean out the dpf, cos it makes the exhaust gas temperature a lot higher burning off any soot in there, and also elsewhere in the engine.

    Advice we’ve been given by all the VAG techs we’ve spoken to was was to run it at a steady 2500 revs for 10 mins or so if the light comes on, rather than completely thrash the thing – ideally in 4th (cruise control helps), but I’ve also managed a regen in 3rd on country lanes. You need a constant running temp to clear the filter apparently rather than loads of peaky revs. It only comes on occasionally now, and the above always clears it pretty quickly.

    ElShalimo
    Full Member

    thrashing it won’t help in the long term but 70mph in 4th gear for 20mins will probably get the exhaust temperature nice and high

    Mazda 6 EGR valves often gfail due to the particulate build up in the DPF

    doctornickriviera – Member

    – good luck mate, it’s a bugger to get fixed

    doctornickriviera
    Free Member

    I know! Fix sell and never buy another mazda!

    innit_gareth
    Free Member

    Had one removed on a 54 plate bmw 5 touring. Done 100k miles.

    Eventually had a bypass pipe and remap done to cure loss of power after spending 700 on exhaust manifold which bmw were 90% sure would sort the loss in power.

    This didn’t fix loss in power and BMW diagnostics flagged the DPF. Didn’t want to spend the 1500 on the dpf when I wasn’tsure it would fix it. So had the bypass and remap done (badly at Longlife exhausts once they’d hacked the cat off thinking it was the DPF).

    Didn’t fix loss in power – next problem was according to BMW “probably” turbo at which point i sold the car on the bay having spent 2 grand trying to fix the problem.

    From all the hours and hours of research i did it seemed like the pricey dpf is a total cludge of a fix for euro V emissions. And Trainer BMW and prob most main dealers would be were only too happy to replace one expensive part after another without using donor parts to find the real cause of the loss in power problem.

    Moral of the story – don’t always assume its only the dpf : could be faulty turbo causing oil to clog up the dpf.

    orangina
    Free Member

    Rickmeister here:

    has anyone had a DPF removed and passed the emission test on the MOT ??

    Yep, its a smoke test on diesels.

    Blazin-saddles
    Free Member

    My VW T5 has had a DPF delete and remap too, It used to have a problem occasionally dropping into limp home when cold but since deleting and removing it hasn’t done it since, it flew through it’s MOT at the VW main dealers too.

    supertacky
    Free Member

    Most dealers rely totally on what the diagnostics computer spews out.
    Exhaust gas recycling unit and swirls valves are another emissions based moneyfest for dealers who pray on unsuspecting Diesel owners.
    No manufacturers are above this. The higher priced brands just cost more to fix.

    Last week a guy I know was fleeced for £750 for a new cam chain by Honda, turns out it was a £23 +vat sensor that was misreporting to the ECU.

    molgrips
    Free Member

    A road trip to Germany is also a good way of cleaning the DPF out. 300 miles of driving as fast as the car goes does a pretty good job 😉

    (NB I didn’t do this – at top speed of 130mph our Passat wasn’t particularly confidence inspiring and pretty noisy – it’s also too fast to keep up with the normal traffic at 100 ish but not fast enough to get out of the way of the proper fast cars)

    supertacky
    Free Member

    That’s the best DPF thrashing idea I’ve heard yet! Good work Molegrips

    Taff
    Free Member

    Removed on 306 turbo diesel, no change to turbo or fuelling and made little to no difference to the smoke test

    molgrips
    Free Member

    Tacky – 🙂 the car ran very nicely the whole time we were in Germany. Re-acquired the slight misfire on cold issue though, but now that seems ok again. Odd.

    supertacky
    Free Member

    Molgrips – EGR?

    Easy to clean, even better to blank off completely!

    molgrips
    Free Member

    Dunno. When I got it, it’d jerk maybe three times as I was driving down the drive from work – very light throttle and maybe 20mph. Not every time though, but often. I did loads of UK motorway and it went away. Well I drove all around Germany (fast) and towed the caravan all the way home, which put a lot of heat through the engine, and the very next day after arriving it did it again. Had it for a month or three, now it seems ok.

    The best I can think of is an injector issue or perhaps the injector wiring. It could be worse in really wet weather… But you’d expect a light to come on if it was having trouble talking to the injectors. I can’t imagine it’s something actually failing because it did it at 46k and didn’t come back until 82k when it’s the same. You’d have expected it to gradually worsen, not go on holiday and come back the same after double the miles..?

    EDIT: hmm.. EGR.. caravan towing would be relatively high throttle but low revs.. possibly a lot of EGR being used.. interesting. I wouldnt’ delete it though, I don’t want to spew out any more NOx than I have to.

    oliverd1981
    Free Member

    Can you remove them by whacking a long 30mm wood drill up your Exhuast and coring it out?

    owenfackrell
    Free Member

    molgrips – Member
    I think Ford are the worst. The different manufacturers use different regeneration strategies. I think it’s Ford where you have to refill the additive to keep it working, and apparently plenty of people don’t even know this and ignore it. VAG and I think PSA don’t use an additive.

    supertacky – Member
    Yeah your right Molgrips Renault, Ford, Volvo, Mazda all have DPF additive tanks which inject a catalyst into the diesel tank each time you fill up. Good for about 250 shots IIRC. Once empty the DPF in the exhaust struggles because its not close enough to the engine to heat up quickly.

    Ford engines were developed with PSA who developed the system for pasanger car use in the first place so yes they do use the addative. Renault dont use addative but they do inject extra fuel. The only volvo engine that use the addative are the ones they got from ford the D5 and its new derivatives do not.
    The addative coats the particules and cause them to have a burn at a lower tempurature. The car needs to be run at motorway (engine) type speeds for around 20 mins for the DPF to burn off the soot. There were a lot of cars that were (and proberly still being) miss sold to people as the sales men didn’t understand the requirments of the dpf and the fact that they will not work and quickly clog if the car does a lot of short/startstop journeys.

    duckman
    Full Member

    I am going through this particular hell in my pug 407 estate. Last piece of french ca I will ever own 😡

    supertacky
    Free Member

    “Can you remove them by whacking a long 30mm wood drill up your Exhuast and coring it out?”

    Answer is no. The pressure differential sensor measures pressure at the front and back of the DPF and if its not within limits it throws a fault on the ECU. Too much or too little pressure creates a fault and possible Limp mode.

    supertacky
    Free Member

    owenfackrel – I stand corrected its Volvo, Ford, Mazda and Peugeot (not renault) that use fluid adative. Very expensive at around £40 a litre. My ford took about 2.5 litres to refill last year.

    supertacky
    Free Member

    I’ve also heard of people removing the DPF by smashing it out refitting it and then fooling the ECU by fitting a resistor of correct value at the end of the wiring harness instead of the pressure dif sensor.

    Still need to replenish the aditive tank every now and again though

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