2012 Ford C-Max diesel emissions smoke fail

30 Dec 2008
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United Kingdom
Hi All, My niece's car has just failed its MOT. It's the 1.6 diesel. First smoke reading was over 3, average got down to 1.63. The compliance plate on the door pillar puts the limit at 0.55, so it's still a mile off! As yet, I don't know how many miles it has done. She's not famous for looking after her cars, so it probably hasn't been serviced for a while.

I'm guessing that as a 2012 car, it should have a DPF? If so, I can't really work out why it is emitting ANY smoke, to speak of, at all? She has no warning lights on, and the car (I'm told) drives fine. She's had it about 5 years and it has managed to pass MOTs so far, although I'm told it struggled on smoke last year, but just scraped a pass.

Last weekend, she took her family to North Wales in it, so it got a bit of a run, and she put some Redex injector cleaner in it for the run, so it should have had a reasonable clearout. They've tried taking it for a thrash, but that still hasn't helped.

Any thoughts, anyone, please?
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Not sure on this particular car but on mine you can undertake a forced regen of the dpf. You can also use dpf cleaner which lowers to temperature required to clean the dpf. Made by redex and goes in the fuel tank.
A new air and fuel filter and a good thrash on the way to the test station, remove the manufacturers plate and it should go through a fast pass which I think is 1.5. But I haven’t done a test for a few years now.
Thanks both. I was wondering about the label meeting with some "unfortunate accident"... ;) It's amazing how often people inadvertently trap the seat belt buckle in the door shut when they slam the door, and it scratches the smoke figure off the corner of the label. Really, manufacturers should have to put it in a more prominent position... I'm just a bit wary of doing that, as it's a retest, so they know what the value was last time they checked it!

However, I'm also genuinely curious to know what the root cause is, because I'd have thought a blocked or malfunctioning DPF would put the engine management light on?
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How many miles has it done? It may be worth thinking about replacement injectors. To regen the dpf you may need to run it at 75 mph for about an hour and have a full fuel tank.
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I've asked about the mileage, but she hasn't come back to me yet. They took it to North Wales with the family in it last weekend, so it probably got about a 50 mile continuous run with a bit of load in it. She's notoriously bad at looking after her cars. Her previous one was a 2004 petrol Touran which she never serviced. Just drove it, collecting more and more warning lights until it finally stopped and scrapped it. I imagine this one will have been through the same meticulous maintenance regime!

I'm talking to a guy from Ford who I have dealings with at work. I've given him the VIN and he's going to see if he can find anything out. Apparently, they did have some that suffered cracked DPF substrates! I'll report back if he comes back with anything useful!
Take it somewhere quiet and hold it at full throttle for half an hour!
Under no load?! :eek:
Could put it in gear and slip the clutch a bit. ;) Only joking. Perhaps hold it at 3000rpm. I was thinking if my VW where it won’t rev past 3000 of not in gear and moving.
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Anyway, thanks guys, but chatting to her mum this evening, it seems she's decided to scrap the car and get another one! She did this last time too - drove her Touran into the ground and then scrapped it. Broke my heart, it did - a really solid car that probably just needed a decent service!

I'll let you know if my Ford guy comes up with anything. At least it might help someone else...
Surely not scrapping a 2012 car?. Take it off her hands, follow the advice above and make a few quid!
Surely not scrapping a 2012 car?. Take it off her hands, follow the advice above and make a few quid!
She's got form! She did this with her Touran when it was even newer! If I lived closer, I could have saved that (and probably this one)...:cry:
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