DPF - Clean or replace?

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RichardW
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DPF - Clean or replace?

Post by RichardW »

307 needs its cambelt doing, and I thought whilst I had the coolant dropped I might as well take the opportunity to take the DPF out and clean it (as it needs the rad removing). It's done 115k now, and MPG has dropped back from 55 when I got it to around 50 now, and I put Diagbox on it last night and took it for a run, and it is going >100 mbar pressure drop under load. I see GSF do a cleaning fluid, which appears pretty benign (although I am not sure what you would do with the drainings!) - it's quite pricey though at around £60 (eg on e-bay. Or I can get a new filter for around £135. What thoughts? Despite the extra cost I am leaning towards the replacement as the outlet flange on the current one is starting to look a bit scabby (undertray is AWOL!) although I imagine I could fabricate a new flange if I had to.

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NewcastleFalcon
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Re: DPF - Clean or replace?

Post by NewcastleFalcon »

I think at those price differentials, and bearing in mind its probably a good time to do something with it, I would replace. Then again I would probably have a look at you tube and find someone using a jet washer on a DPF, with a satisfying stream of black gunge emerging, and think what's there to lose?

Very topical for me this very lunchtime, as I have just had to carry out the regeneration of the DPF on a Fiat Long Wheel Base Van (not my own) Its a van that needs a good seeing to as the frequency of regeneration is now around 150-200 miles! and just 30,000 miles on the clock. Yes I'm all for removing the particulates but the 10 minutes of a regeneration must be nearly as bad, it certainly smells not too good for your health.

Regards Neil.

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jimmymarsbar
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Re: DPF - Clean or replace?

Post by jimmymarsbar »

I've just done this on the works 307 SW 1.6 - I think it's the BTED4 engine, I might be wrong though.

I took off the DPF/cat without having to remove the radiator - I just had to take a bit of care with the heat shield!

The car was spewing all sorts from the exhaust, and looked like any attempted regens were in vain. The cat was fine, but the DPF was caked.

We debated about getting a new DPF, but the decision was that it's too much to be spent on the car when a huge improvement could be made by cleaning it.

I used a whole tin of aerosol solvent cleaner followed by a scorchio jet wash - the difference was more than noticeable.

After the initial cloud of soot out of the exhaust, the smoke was a normal colour, the engine sounded happier and the performance was much improved.

The only tricky bit was rejoining the cat and the DPF - it took a fair bit of persuasion!

I don't know how effective the cleaning method is long term, but I'd recommend giving it a go before splashing out on a new DPF.

dnsey
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Re: DPF - Clean or replace?

Post by dnsey »

As a compromise, there are firms around who will professionally clean your DPF using specialist equipment and chemicals. You can usually either send them the filter, or make an appointment for them to remove, clean and refit it.
Apparently the cheap aftermarket DPFs use a different substrate, which is vulnerable to melting under regeneration.

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spider
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Re: DPF - Clean or replace?

Post by spider »

My thoughts on this are if the casing itself is sound (and not likely to rot and fall apart within a few months at least) then as above a good pressure wash out ideally with something suitable (painters panel clean / gun-wash maybe?) would not really be a waste. Worst case scenario is you break it and have to replace it which you'd otherwise have to do anyway.

I (think) it is meant to actually *be* replaced at specified intervals anyway but typically its not usually indicated in the schedule as a 700ish 'filter' on a service can make peoples eyes water...

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Stickyfinger
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Re: DPF - Clean or replace?

Post by Stickyfinger »

As with CATs, I would not like to fit an after market DPF, as such I would consider it a good bet to clean the original one and refit.

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spider
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Re: DPF - Clean or replace?

Post by spider »

Stickyfinger wrote:As with CATs, I would not like to fit an after market DPF, as such I would consider it a good bet to clean the original one and refit.
Oh I'd agree. There is no harm (and not a lot of cost) in attempting to clean a DPF really. If you break it or are unsuccessful you are not really much worse off as you'd of otherwise replaced it anyway... :)