Citroen DS3 1.6 hdi black smoke from exhaust

[PaulC5]

If your dpf is damaged internally then cleaning it may not help. Maybe you need to remove it to see how bad it might be.

[CitroenJohn]

I have been on the brink of buying a second hand DPF on eBay but really I don't know what I would be buying. Secondly, I was on the brink of taking mine off and having it properly cleaned by the company mentioned in my last post. Then the two bottles of DPF cleaner and regenerator arrived today (okay, I know you are going to tell me that won't work) and I stuck that in a full tank and went for a blast. Following that I put my OBD 11 tester on the car again and this time it did provide me with a fault....P 3007. I did a search on here and found some posts saying it was to do with air flow etc in the fuel system. One post showed a pipe which goes between the EGR valve and the big fuel intake pipe going from the throttle body to the head and this pipe was all crudded up with black stuff (technical term). So, thinking there may well be other things contributing to my smokey exhaust, such as the EGR valve, which should be fixed before the DPF, I decided to take this pipe off and found it was gunged up with horrible black matter, hard, soft and in-between, which was restricting the flow down this pipe and into the intake pipe from the throttle.

I cleaned this pipe up and as far as I could into the intake pipe, but couldn't really see into the EGR valve itself - presumably this may be in a similar state and will require removal and cleaning; not such an easy job as it appears to be part of the cooling system - unless the EGR valve comes off by itself and leaves the rest of the body intact. It's hard to tell without having one on the bench.

I have taken photos but am not sure if I can post them on here. Anyway, I have done something and found something and made some progress at least!

[Hell Razor5543]

It is simple to post pictures on the Forum. Click on the 'Full Editor & Preview' button, then click on the 'Attachments' tab, then the 'Add files' button, browse your files and select them.

[CitroenJohn]

Here are some photos of what I found on my engine and a video I found on YouTube showing the removal and cleaning of the complete EGR valve assembly. Having just posted the link that I copied and pasted, it says the video is unavailable but I will try anyway in case it works.

My plan is now to remove the EGR vale and components and clean them up properly and also to take the DPF off myself and clean it with 5 Litres of Wynns DPF cleaner, plus maybe a flush with detergent to remove any oils remaining. This will be later in the week when I have a couple of free days.

So does the built up of carbon and oil and soot in my pipes happen on every diesel our is there something amiss with my car? Everything going through the DPF and the EGR comes from somewhere within the engine by one route or another, from combustion, oils, vapours etc. I am still getting my head around the way this all happens but I am learning quickly by taking things apart. Obviously, regular oils and filter changes help here, as do regular fast runs and revs to aid regeneration, but the computerised monitoring system, sensors, switches etc should take care of most of this automatically. I wonder if there is something wrong with my car in that no warning lights have come up on the instrument panel. Also, some oil has come from the PCV valve on the top cover and found its way past the turbo, through the intercooler and thence back into the inlet manifold via the throttle housing. I am waiting for a new PCV valve to arrive as I suspect it may have been fitted wrongly and the cover on it is not a tight fit as oily vapours seem to escape around the sides of its lid.

Since I got the car at 43,000 miles it has been used mainly as a driving school car and so doesn't get as much high speed running as it might, although it is very often on dual carriageways so it does get some exercise! The way I drive myself is more about fuel economy and Eco Driving as opposed to racing starts and harsh acceleration / braking. So I guess my gentler style of driving doesn't help things. When I am not teaching and actually going somewhere I much prefer to use my 20 year old C5 Tourer anyway, since it is a much nicer car and has real suspension instead of the "Go Kart" suspension on the DS3!

To say that things are a bit clogged up the car still goes like a bomb and shows no lack of performance. For now I will leave it until later in the week and have another good go at it then. I seem to be doing little else but mending cars at the moment.......which reminds me.... the 19 year old VW Transporter I bought and converted into a camper van has decided that its passenger door window has come off the rails (or whatever), so I had better get the door card off that and see what's happened.

I hope this link works as it is quite entertaining, despite my not doing able to understand a word he says. Actually, this is not the video I meant but it is similar.

[CitroenJohn]

I have now completed what I intended to do to sort out the smoke problem from my 1.6 Diesel. I contemplated spending £200 on having the DPF professionally cleaned, but having the need to take it off anyway I left it soaking overnight in 5 litres of Wynns DPF cleaner and then washed it out with a hosepipe. This seemed to work very well and a lot of carbon and soot came out, so that what little I can see inside the filter looks pretty clean.

Yesterday I tried removing the EGR valve, but being such a swine of a job on this car I didn't get much further than I did before by removing the previously gunged pipe which goes from the EGR valve to the inlet pipe which goes on to the cylinder head. From what I could see with a small mirror, things didn't look too bad in the pipe and the EGR itself, so I did what I could with a small paintbrush and a rag to clean as far as I could reach.

I think the other contributing factor to things having carboned up and/or smoking is the fact that oil was getting past the engine's PCV breather valve into the turbo and beyond. I have fitted a new valve cover, springs, diaphragm etc and the cover seems to seal much better than the old one, around which fumes could be detected. So hopefully, that might stop the oil going through to the turbo.

I took the car out this morning for quite a long and sporty drive and the smoke problem is hardly there to be seen. I did some really hard accelerations with very little smoke and the tailpipe is a lot cleaner too. Altogether the engine pulls better and performs better and quicker than it was doing. So I reckon the DIY cleaning option for DPF's is well worth a try if you want to save £200 or so (even more if you include the ERG valve which might just need cleaning), even if the result isn't quite as good. Now, I'm going to look at my 2003 C5 Estate and have a look at the EGR valve!

If you do the DPF cleaning, the insides will obviously be a bit damp. I had to do a few miles up and down hills before it got warmed up and dried out - until then, by the amount of white vapour coming out the back of the car would have made anyone following think there was a steam engine under the bonnet! Thanks to all for advice.