DPF wash out and rebuild

[Greg Roles]

Anything is going to help. I figure opening it up entirely is the best way, but I am sure a firehose reverse flush would gain you a good amount of capacity back. I am still doing a lot of trial and error testing, but do believe I can now accurately work out how much ash is remaining so you can set up the DPF post washout to regen properly. You have to set the ash level in grams to an accurate amount, so the ECU can work with the pressure difference, and not over or under regen. This is paramount, but I feel I have pretty much cracked it.

Here's the thing. My DPF was at about 40 grams of carbon ( ash levels ) and that is the end of life capacity. I'm pretty sure that I'm now back down to just 4 grams. Vag Com states a clean / new DPF should have a pressure difference of between 4-9mbar at idle, and get this, my washed out core is sitting at 8.5!!!

So in a nutshell my washed core is within NEW range!!!!!!!!!!!!!

I've still a lot of testing to do, and will report on the results, but at this stage I am of the opinion I have a good as new core, and am 99% convinced that this procedure can be used to effectively regenerate any SiC ( ie all VAG ones ) core that is still intact. My MFD range per tank has gone up as well, and the car is definately performing better. I am monitoring regens, and it would seem it will be a towards a tankful before another one happens at the very very slow rate of fill. This is how it was when I bought the car : )

I'm rather pleased with myself!

[popeclement]

an excellent post - out of interest what would be the comparative costs of a dealer supplied and an OEM replacement (if available) DPF assembly ?

[Umai Naa!!]

Around $3,000 supplied and fitted through the dealership, at a close guess.

[Greg Roles]

It was a bit over $4k for the Golf when I got it, seems VW dropped their prices to a little less ludicrous lately.

You can get a rebuilt pipe out of Europe for about $1200 or so, but the ones available on Ebay etc have become of poorer quality lately.

I'd have to say anyone with a clogged core should try a washout, and this year I hope to be able to offer new standard cores, and higher flow "sports" ones, so you can turn the damn regens off altogether, comes down to legalities and how little soot I can get it to blow. I believe I can make it meet Euro V, but the latest MK6 level Euro VI emissions, well that is highly unlikely. Still you MK6 types should have a bit of time left in your DPF's, it's the older diesels like mine that are starting to clog on mass!

[gecko2k]

Good work there Greg, some DPFs can also be pressure cleaned with an air hose and compressor, can get messy so you need to have a water bucket or old towel at the other end to catch the soot


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[Diesel_vert]

Part of the Euro 4 emissions requirements stipulates an in-use durability requirement of 100 000 km, so at least your DPF has lasted beyond that.

Interestingly, that requirement was increased to 160 000 km for Euro 5 vehicles, so hopefully the DPF on the newer cars will last a little longer before they need "servicing".

[Greg Roles]

Any DPF equipped car is at least Euro V mate, so I got robbed! The MKV 103kw Golf and the Polo's etc all had no DPF and only met Euro IV.

I reckon the MK6's will last longer overall, as they have separated the cat component with a pre cat and post cat, and common rail is far more DPF friendly, produces far less soot overall, far better mixtures. My next diesel will definately be common rail....and not front wheel drive!!

[benough]

Just quickly Greg.

What's the VCDS code to see the ash level?

I know it's under engine. My GT TDI is at 155,000km and it's rare for it do an active regen. Maybe every 6 weeks or so?

[Diesel_vert]

Any DPF equipped car is at least Euro V mate, so I got robbed! The MKV 103kw Golf and the Polo's etc all had no DPF and only met Euro IV.

I reckon the MK6's will last longer overall, as they have separated the cat component with a pre cat and post cat, and common rail is far more DPF friendly, produces far less soot overall, far better mixtures. My next diesel will definately be common rail....and not front wheel drive!!

The Golf Mk5 GT TDI was a Euro 4 vehicle, as were Golf Mk5 TDI models without a DPF.

[jazd]

Good stuff Greg, great results. I would also say from my experience that it would be pretty hard to remove all the ash with even a high pressure hose without taking the core out.

Just quickly Greg.

What's the VCDS code to see the ash level?

I know it's under engine. My GT TDI is at 155,000km and it's rare for it do an active regen. Maybe every 6 weeks or so?

Its not a code, its one of the measuring blocks. Mine was also pretty healthy at 120,000km or so and had a tune since 80,000.