blocked diesel filter :(

[rlatarche]

Hiya guys (and girls),

Im after some help please - recently bought a 307 SW 2.0 HDi 110 (123K miles) and now have the blocked diesel filter message on the mfd.

Ive had the car up on a ramp and have just found out to my disgust that the DPF is in fact one of the early designs and has the cat and DPF all in one. (It looks like the others but is welded together rather than bolted together.

Am I now unable to flush the dpf? Im worried about damaging the cat and was thinking maybe a few small reverse pulses of compressed air may help.

My brother in law has an Omniscan device that can force a regen, however im sceptical as to whether this will clear the problem.

Anybody had this issue before? and been able to resolve it without replacing the cat/dpf?

Thanks

[jmkent]

Don't go doing a forced regen in that way unless the car is in tip-top condition - it puts quite a strain on the engine, I'm lead to believe.
Best bet is to take it for a 20min drive or so on motorway and keep revs at 3000 all the time and it will do the same as a forced regen. Take it that it hasn't gone into limp mode? If its really bad, this could cause damage to the turbo if too much back pressure is present, but if it has only just come up, you should be OK.

[rlatarche]

its been coming on and off for about two weeks - engine management light comes on mfd states filter blocked then seems to clear itself in a couple of miles - only comes on when i push the car a bit hard. Ive had the car at high revs on the motorway for quite a while with no effect (no notice of regen etc)

ive checked the fuel additive and its about 33% full

[jmkent]

Have you had it scanned with Planet? It may be a fault with the additive dosing system not putting it in each time you fill up. Before splitting the cat/DPF apart, I would find someone local to you with Planet to do a scan and see if there are any problems that need attention first. Check the Planet owner's map under the Maintenance and see who is close to you.

[chopper1192]

123K - it'll probably be caked, and the low additive level is proof the system simply needs a full service. Always assuming something isn't broken and causing these messages, you need a new DPF/CAT unit. No way round it on the older sealed type.

[rlatarche]

No haven't got it on a diagnosis unit yet, the brother in law has an omniscan unit and he'll scan it tomorrow. So due to the fact I have an "all in one" unit I have no hope of cleaning it.

[Hysteria]

Buy a second hand one from a scrappy (some times you get lucky) that can be split into two sections.

Actions speak louder than words: DIY FIX Blocked Particulate Filter on Pageout 307 HDI 110BHP.

If you can't get 1 there is 1 method that will work but make sure you have a lot of space around you and plenty of gas.

burning a FAP filter - YouTube

burning a FAP filter - YouTube

Basically you reverse burn your DPF/CAT with gas, the idea is to get the filter to about 500 degrees C which is enough to start a reaction without additive.

DON'T try back washing a sealed DPF/CAT as you will only force the crud into the CAT and make bits of it.

[rlatarche]

Originally Posted by Hysteria

Buy a second hand one from a scrappy (some times you get lucky) that can be split into two sections.

Actions speak louder than words: DIY FIX Blocked Particulate Filter on Pageout 307 HDI 110BHP.

If you can't get 1 there is 1 method that will work but make sure you have a lot of space around you and plenty of gas.

burning a FAP filter - YouTube

Basically you reverse burn your DPF/CAT with gas, the idea is to get the filter to about 500 degrees C which is enough to start a reaction without additive.

DON'T try back washing a sealed DPF/CAT as you will only force the crud into the CAT and make bits of it.

So what "gas" are they forcing through the DPF - I read the thread that you linked to and in the comments there are several people that have back flushed the combined unit successfully.

Also is the split dpf and cat a direct replacement for the combined unit? i.e. all the connected pipes are the same length?

Thanks

[Hysteria]

Acetylene gas, normally used for welding but if the burner is high pressure and set to wide flame it gets into every corner of the filter (not to mention everything else.

Other option is to fill the thing with industrial alcohol and set it on fire

[rlatarche]

so had the brother in law hook it up today after doing a load of work on the front suspension (so nice having a car that doesn't knock over ever bump and pothole )

and this is what the reader came up with:

P0380 ADDITIONAL HEATING CIRCUIT 1

P1435 ADDITIVE SYSTEM

P1521 CLUTCH SWITCH CONSISTENCY WITH VEHICLE SPEED

P1448 PARTICULATE FILTER

going to scour the net now for explanations/possible solutions to all of the above - feel free to add your ideas!

As for the gas through the cat/dpf the father in law is a welder by trade and has bottles of welding gas etc - is the gas just passed through the unit and it ignites itself or is it just lit and then pumped into the filter?

thanks