DPF wash out and rebuild

[Ideo]

Well, probably mate, but I can't see a Jap DPF being 3-4K to replace...

I've seen a 8k quote on a Mazda 3 Diesel...

[Greg Roles]

Yeah the Mazda's have a whole extra level of complexity, and I'm only just getting my head around it now. They are a NIGHTMARE compared to the SiC Vag and most Euro cars use, but clever in some ways too. Absolute bitches when they go wrong from what I have been reading.

Yep Poyta I did my whole thing on ramps, but you do need to drop the drivers driveshaft, or at least wriggle it out of the way to get the DPF out, and it has female torx bolts. You need to plan the task ahead of time, and allow a good weekend to do it, the DPF comes out fine, but it's a bit of a chinese puzzle the first time out. Be very gentle with the sensors, easy to upset them. You need to soak them in WD40 for a while before trying to undo them, they can be bloody tight.

Expect skinned knuckles!!

[poyta]

Greg, can you give us some specs the the pressure washer you used? I have a cheapie pressure cleaner but not sure if its ample enough to do the job.

[Greg Roles]

Karcher 2.54 with three pressure settings, I used it on flat out. It's an old model now - but has a max 100bar pressure at 400 litres an hour. They are going to be dead cheap this Queens Birthday weekend at Supercheap I reckon!!

[Harpo]

I have just bought a lovely MK5 GT diesel with only 60K on the clock and the DPF is stuffed.
Have had performed numerous forced regens and completey remove DPF and soaked in moly cleaning fluid over night worked OK for 200 klm intervals for a while and then limp mode. Approx cost so far $1300.
... anyway Greg is your squiky clean DPF still going good?

[poyta]

I have just bought a lovely MK5 GT diesel with only 60K on the clock and the DPF is stuffed.
Have had performed numerous forced regens and completey remove DPF and soaked in moly cleaning fluid over night worked OK for 200 klm intervals for a while and then limp mode. Approx cost so far $1300.
... anyway Greg is your squiky clean DPF still going good?

What makes you think the DPF is stuffed? Have you tried some Liqui Moly DPF cleaner? I've had fantastic success with it. Read up on my experience here Liqui Moly DPF cleaner

[Harpo]

DPF is probably OK just clogged with ash. Have soaked overnight in Liqui Moly DPF cleaner.

[ian]

Well I have the same car ,Gt diesel with 58,000 on the clock and have never experienced a Regen, ]Not to my knowledge any how]
I always drive it in a spirited manner, even though i'm retired but ive always had performance vehicles and drive them accordingly,
What would be the first sign of the DFP being clogged?

[Greg Roles]

Regens are happening Ian, every 800kms. It's when the idle raises to 1000rpm, and the car can feel a bit jerky, and induction noises rise. If you had an EGT gauge you could see it more clearly, the car does them automatically at this sort of interval even if it's not needed as a failsafe. Your DPF will start showing signs of clogging after 100,000kms typically and you will start to see DPF lights and notice regens more often as it's capacity decreases.

Yep my renewed DPF is stil going well at 165,000kms now, so it's had a further 60,000kms, I would suggest anyone with a clogged DPF look at getting it professionally flushed, liquimoly DPF cleaners only remove the soot through the Cerium catalyst, but not the ash which is the WHOLE problem, and that needs to be pressure washed back out. There are places that offer this service now.

A proper sports DPF solution will happen, but not in the short term, a lot of testing still required, and I'm not releasing anything till legally approved, so it has to meet emissions. That is unlikely to happen for the MK6 cars anytime soon if at all, but for the MKV it's looking pretty good.

[Harpo]

Feeling inspired/frustrated I proceeded and after a few hours the DPF was out. Hopefully this will be quicker going back in. You need a good set of tools and it was Ok with just 2 small stands under the front. Helps to have a patient mate also to pass tools and wriggle the DPF out.



I notice that only soot came out and not ash as per Greg Roles. This could be because it was recently had Moly treatment. Greg you are right about the insulation sleeve being fragile as it feel apart after getting wet. Not to sure what to use as insulation now.

My other TDI 1.9 Golf has no DPF and only puffs a little smoke under hard acceleration and this GT has common rail so less smoke maybe? DPF in/out heads or tails.

So in hindsight when buying a second hand diesel car with DPF should use diagnostic equipment to check out clogging to avoid a time bomb OR go for GTI ( non DPF) not GT as fuel consumption and torque is improving eg MK7 GTI

Anyway feeling much better now after knocking the grap out of DPF. The big question now DPF in ( just labour)/out (>$1500 remap ECU)?