Removing the DPF for cleaning - but how?

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nizzehult
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Removing the DPF for cleaning - but how?

Post by nizzehult »

After almost two years of various problems I decided to clean the DPF of my C3 1.6L HDi -07. Not by any magic sprays or fluids; my plan was to remove it from the car and use a high pressure washer to clean it and then reinstall it again. I have read a number of successful stories when people have done that.
Removing it is tricky, the plate between the cooler and the engine has some really hard-to-get bolts ...

Anyhow, after a few hours I succeeded in loosening the big clamp under the plate that holds the filter.
But ... how on earth can I pull it out? The filter itself is a huge thing, about 15 cm diameter and 15 cm thick and when the clamp is removed only 3-4 centimeters are visible, the rest is tightly hidden in the cylinder (called pre-catalyst). The only way to get it out must be to pull it exactly right down but how? I can turn it 5-6 cm but it only moves sideways, not down. There is no flange or any sharp edge where you can bend or in any way or hook up some kind of tool.

You people who have done this: how did you do it?

Here's a picture:

https://imgur.com/a/ZsW7toR
RichardW
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Re: Removing the DPF for cleaning - but how?

Post by RichardW »

Take the whole unit out, and split it on the floor. You will need to remove the heat shield, which may need the radiator removing to get enough room.
nizzehult
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Re: Removing the DPF for cleaning - but how?

Post by nizzehult »

I have the Citroën service manual and it says that the filter can be removed without removing the radiator. They suggested moving the AC compressor to access the last bolt for the heat shield but I managed to remove it using a very special "angled" socket wrench.
Taking the whole unit out means even more work so I'm not happy with that alternative ... but I got a tip from another forum: use a wide screwdriver and bend out all the metal lips a little bit that is surrounding the filter. I'll try that tomorrow!
nizzehult
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Re: Removing the DPF for cleaning - but how?

Post by nizzehult »

Yeah! Bending out the lips did the trick! The DPF is now removed. I started with compressed air to clean it and I hardly saw my neighbours house during this operation...
Now I have sealed the bottom and filled it with some stuff I bought that is made for DPF-cleaning, it will remain there until tonight. After that I will use a high pressure washer and when the water is clean I will resinstall it.
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GiveMeABreak
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Re: Removing the DPF for cleaning - but how?

Post by GiveMeABreak »

Be very careful - depending on type, the honeycomb matrix can be sensitive and has been known to crack / crumble if too harsh a force is used.

When you have it refitted, you will have to use Lexia to tell it you have replaced the DPF and I would also suggest topping up the additive tank at the same time (then reset the additive counter afterwards). This will tell the engine ECU that no additive has been dumped into the filter. If you don't the ECU will mis-count when it thinks the additive needs topping up and may also flag up a DPF warning if it thinks you have dumped the maximum amount of additive into the filter.
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Stickyfinger
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Re: Removing the DPF for cleaning - but how?

Post by Stickyfinger »

nizzehult wrote:
05 Jan 2020, 11:23
I started with compressed air to clean it and I hardly saw my neighbours house during this operation...
:)
nizzehult
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Re: Removing the DPF for cleaning - but how?

Post by nizzehult »

I was aware of this and the high pressure washer should be used with care, not using the highest pressure and not be too close to the matrix when using it.
Refitting was tricky though, especially the pipe to the diff-sensor. I'm not even 100% sure that it's not leaking around the filter. Anyhow: a small leak is no big issue.
DFP Replacement procedure has been done in Lexia, yes, but I didn't have any eolys for topping up the additive tank.

First drive was OK and I can almost imagine that it is a little stronger now on low rpm's. No warnings or other issues. Halleluja! :-D

I've written a complete how-to guide posted on another forum. In swedish, though.