Antipollution/unblock Diesel Filter Faults

[bradajee]

Hello. I bought a 2004 C8 2.0 HDI SX with these faults as the owner said he'd taken it to a garage and they put it on a diagnostic, to be told that it is a faulty diesel filter sensor. I knocked him down £100 because of this. The faults put it into limp mode, no turbo at all :-(

After getting it home I Googled the faults and there's a few different thing that could cause them. The sensor being around £50 plus fitting, or the filter itself (many hundreds of quid), or the eolyn? liquid needs changing (again many hundreds of quid) etc etc.

After I had the it for 2 weeks both faults reset themselves and I had a perfect running car ! But a week later the faults came back. Since then in the last 2 weeks the faults cleared themselves once more but only for about 5 mins then came back.

Anyone knowledgeable enough to give an educated opinion about the probable cause of the faults please as I'm dubious about the original seller's diagnostics.

Any decent help appreciated as my car does rubbish milage without the turbo :-/

Thanks  

[paul.h]

Welcome to the forum.

 

How many miles has the car done ?

 

Anti pollution fault just means there is something wrong that affects the exhaust emissions so could be anything so you need a fault code reader to see what that could be and it may be a different problem to the filter one. The message unblock diesel filter usually means the diesel particulate filter (dpf) in the exhaust needs cleaning/regenerating. You also need to check there is still eolys fluid in its tank (located somewhere near the fuel tank). To regenerate it you could run the car above about 40 mpg in a low gear for maybe 20 minutes which should burn the soot off. If the eolys fluid has run out there probably would be a message saying low additive level but this is based on miles done rather than an actual measurement.

 

If you went to a dealer they would possibly try a forced regeneration or fit a replacement dpf and top up the eolys fluid but at a cost of several £100. Some people will remove the dpf and water jet it to remove the soot. Removal of the dpf is not an option since the car would fail the MOT.

[bradajee]

Thanks for the reply Paul matey.

It's Saturday tomorrow so I'll drive from Cardiff to Chepstow n back in 3rd at slightly over 3000 RPM which is all my lovely but twit of a car will let me do grrrrr. I've had a few now so will digest the rest of your kind post tomorrow (or maybe not because the 3rd gear thing at maybe 55 mph will work !!)

Get back tomorrow anyway

Thanks again :-)

[bradajee]

103,000 miles. The engine purrs like a kitten, and when the faults went away for that short time it was a flying machine aswell. Oh that 1 whole week :-D

[bradajee]

Hiya again. I tried the high speed low gear thing with no joy. Maybe because it won't let me use the turbo there's not enough pressure to clear the soot ?

 

Anyway does anyone know where the DP filter actually is please? And how hard it would be to physically clean it out myself?

 

Thanks :-)

[paul.h]

If you look at this C8 exhaust picture it shows the dpf section. You should be able to just remove this part and some people seem to water jet them to remove the ash. https://www.google.co.uk/search?q=citroen+c8+exhaust&hl=en-GB&rlz=1T4DKUK_enGB242GB242&tbm=isch&imgil=V2T768I3TcEieM%253A%253B-D8x34W3oEjtHM%253Bhttp%25253A%25252F%25252Fwww.mrexhaust.co.uk%25252Fexhausts%25252Fcitroen%25252Fc8%25252F20-hdi-turbo-diesel-02_408.htm&source=iu&pf=m&fir=V2T768I3TcEieM%253A%252C-D8x34W3oEjtHM%252C_&usg=__OROGCxr0fZABsjmklzpxhu0QJXA%3D&biw=1208&bih=814&ved=0CF4Qyjc&ei=vcl0VOzkB7GM7AaG54HwBA#facrc=_&imgdii=_&imgrc=V2T768I3TcEieM%253A%3B-D8x34W3oEjtHM%3Bhttp%253A%252F%252Fwww.mrexhaust.co.uk%252Fillustrations%252Fbosal%252F408.gif%3Bhttp%253A%252F%252Fwww.mrexhaust.co.uk%252Fexhausts%252Fcitroen%252Fc8%252F20-hdi-turbo-diesel-02_408.htm%3B600%3B221

[bradajee]

Cheers for that. I asked my local garage about the filter and or sensor and they said it was a pig of a job...It doesn't look like a particularly hard job, or am I missing something?! 

Thanks again :-)

[paul.h]

I have not removed/cleaned a dpf but possibly if you are paying somebody, then the harder it is then the more you would have to pay.

[bradajee]

Ah. Good answer lol. 

I'll look into it some more then.

Thanks again, I'll get back soon as I sort something :-)

[bradajee]

Just for the fun of it then. Has anyone got any idea which wire(s) coming out of the bottom of the ECU inhibit the turbo in limp mode please? 

I would dearly love to give it a good rollicking in high speed low gear for half an hour just to see if that actually clears the soot, plus would save a fortune and I would smile when I drive again :-/

[rfhspares]

From what I understand you can connect a diagnostic computer to the car and force it to regen the dpf. It revs the engine up for a while and I think it alters timing slightly making it burn hotter and burn off the soot . Be interested how you got on with this as I worry about mine getting clogged.

[bradajee]

Excellent thanks for that. It does look quite simple, but I think I'll let my garage have a go. Can't be more than an hour's work I suppose. Thanks again :-)

[bradajee]

Right all. I took it to my garage and explained. They had it for the day. They removed the filter and drilled 5 large holes in it then refitted. I picked it up but the fault was still there. Antipollution and clean diesel filter !

BUT, 2 days later both faults cleared themselves. This was 2 weeks ago and I couldn't be happier. It cost me £40 that's all so very relieved :-D

Thanks for all the help people well chuffed !!

[rfhspares]

Thanks for updating the thread. Wonder what drilling holes in it has actually done.

[bradajee]

Looks like it's given enough flow through to fool the sensor into thinking it's unblocked?

[rfhspares]

Holes drilled down through the centre?

[bradajee]

As far as I can tell when the 4 bolts are undone, to split the casing there is filter in either side. I believe they drilled both sides 5 times. How far through I do not know

[paul.h]

Was the garage a Citroen dealer or a reputable one since what they have done has now made the car illegal by effectively removing the dpf. It should now fail the MOT.

[bradajee]

I've been using this garage for years and trust them. if it fails the MOT through emissions then they'd be liable to fix it and I'm sure would honour that

[paul.h]

If you ever got in to a legal dispute with the garage that is one thing but I suspect as the driver you are responsible for the car when using it. Did the garage explain what they were going to do ? If you sold the car you would also need to tell the prospective purchasers.

 

You should tell your insurance company the dpf has been removed since you could find they will not want to insure you since the car would not be up to MOT standard or if they were not informed and you had to make a claim it could be rejected.

 

Have a look at these topics

http://www.citroen-owners-club.co.uk/citroen/topic/20246-c4-paint-quality-2012-model/

http://www.citroen-owners-club.co.uk/citroen/topic/21018-dpf-heres-the-start-of-it/

[rfhspares]

If the holes were drilled inside the filter so it looks perfect from outside and it passes the exhaust emissions test And it's not blowing at all. Mot won't spot it and it's not something an insurance company would check either. Its only a particle filter and could not contribute to an accident in any way. Cat will still be working so emissions will be fine.

[bradajee]

Okee dokee I'll keep everything in mind. Cheers for the info :-)

[bradajee]

Excellent !!

[paul.h]

On the BBC radio 2 Jeremy Vine program 2/2/2015 vehicle modifications and insurers not paying out was discussed. It started with the case of a car that had the sump stolen and resulting engine damage and the insurer had agreed a payout but then saw a picture of the car which has religious stickers on it. They then refused to pay saying the stickers were a modification they had not been told about, even though it had no impact on causing the theft of the sump. There is a BBC article but on the radio the car owner gave more details than in the link http://www.bbc.co.uk/news/uk-wales-south-west-wales-31064998

 

Other people then phoned in. One refused payout was for a vehicle with a Chelsea football sticker which the insurer did not know about. Another was the owner of a motorbike who was knocked off by a car which had been repainted yellow but the car insurer refused to pay out since they did not know the car had been repainted - in this case though after lots of attempts to get paid, the bike owner then let on he worked for the BBC and the money was hand delivered the next day. Somebody then involved in the insurance business said you should declare any changes no matter how small including stickers, since the insurers will find anything to avoid paying. So even if a change has no possible cause to give a claim, the insurer can still refuse to pay out. In the case of a car that has had the dpf removed, you can get a good idea by looking at the end of the exhaust to see if it is covered in soot since I have found on our cars with a dpf the inside of the exhaust looks like clean metal.

 

Most modifications do not cost extra on insurance. Last time I changed my insurance for the C5 I told them it was used for towing a caravan but then realised I had not specifically told them it had a towbar so did this on the renewal - it was no cost but now appears on the documents as a modification (Direct Line). On our C3 we had parking sensors fitted which we told the insurer about, again it was no extra cost and is mentioned in the documents but the small print says it is not covered if not an original fitting (Admiral).

[bradajee]

Thanks for the indepth info. Much appreciated :-)