Failed MOT emission test

eamon

Hello Folks


As per the title today my car (Citroen Berlingo Multispace 1.6 HDI, 2009 model) failed its MOT on the emission test. Its a diesel engine.



Scored 2.98 and needs to be 1.5 or less. Also lots of smoke but I wasn't there to see and that bit of the test may subjective. Anyway it still failed.



The car has been serviced since new as per the manufacturers schedule.


The MOT station (also a servicing garage and they have a decent local reputation) have poured in 2 litres of a cleaning chemical that according to them gives good results. I don't know the brand name and the only two that I can find on the Net are these and the garage has charged me £10 per litre.



https://www.wynns.eu/product/clean-burn-diesel/
https://pmmonline.co.uk/article/the-easy-way-to-lower-exhaust-emmissions/



It didn't work due to the following I filled up last week and there was 3/4 of a tank lift so the cleaning liquid would be over diluted to work effectively. Additionally they asked where I filled up and I replied "a local supermarket". It is entirely possible that I have filled up with less than a quality product but I imagine that it would be nigh on impossible to prove that.


So this is what I have done on their advice I've driven 200 miles, mostly motorway at 75mph and a bit more and in 4th gear and at 3000+rpm to try and get the engine and other bits & bobs sufficiently hot that carbon deposits are burnt away correctly and also to get the amount of diesel down. The car is going back to the garage in the morning and they will pre-test first. (I'm hoping that the high speed driving will have had a positive effect). If neccessary they will add a 3rd litre of cleaner and retest.


Should all the above fail, what else should get the garage to attempt?


Look forward to replies


Eamon

no1catman

Interesting - what is your annual mileage? Where do you normally - mixed driving motorways etc, or short journeys? What was the previous MOT like - i.e. did it pass first time?

I have a similar predicament, but had problems last year - saw the blackened floor where they'd been running the engine hard! Mine, is a Citroen C30 HDi 03. - used to do three to six 320 mile m4/m25 trips a year, but not now, last motorway drive was to Southampton M$/M3 280 miles in April.
Probably get a new (used) car before the MOT.

SHAFT

Was the engine fully up to temperature when tested? It would be interesting to see the results after your efforts.

sevenhills

According to the research, the Peugeot 208 was crowned the most likely to receive an advisory or fail its MOT for emissions.
Joining the 208 are two Citroens - the DS3 and C3 Picasso - in 2nd and 3rd place, and the Vauxhall Insignia and BMW 5 Series complete the top five.


https://www.express.co.uk/life-style/cars/963371/diesel-car-exhaust-emissions-MOT-test-2018

worried_jim

I've heard to test it with Shell V Power diesel if having an issue with emissions/smoke test. Good luck!

Jumblebumble

eamon wrote: »

Hello Folks


As per the title today my car (Citroen Berlingo Multispace 1.6 HDI, 2009 model) failed its MOT on the emission test. Its a diesel engine.



Scored 2.98 and needs to be 1.5 or less. Also lots of smoke but I wasn't there to see and that bit of the test may subjective. Anyway it still failed.



The car has been serviced since new as per the manufacturers schedule.


The MOT station (also a servicing garage and they have a decent local reputation) have poured in 2 litres of a cleaning chemical that according to them gives good results. I don't know the brand name and the only two that I can find on the Net are these and the garage has charged me £10 per litre.



https://www.wynns.eu/product/clean-burn-diesel/
https://pmmonline.co.uk/article/the-easy-way-to-lower-exhaust-emmissions/



It didn't work due to the following I filled up last week and there was 3/4 of a tank lift so the cleaning liquid would be over diluted to work effectively. Additionally they asked where I filled up and I replied "a local supermarket". It is entirely possible that I have filled up with less than a quality product but I imagine that it would be nigh on impossible to prove that.


So this is what I have done on their advice I've driven 200 miles, mostly motorway at 75mph and a bit more and in 4th gear and at 3000+rpm to try and get the engine and other bits & bobs sufficiently hot that carbon deposits are burnt away correctly and also to get the amount of diesel down. The car is going back to the garage in the morning and they will pre-test first. (I'm hoping that the high speed driving will have had a positive effect). If neccessary they will add a 3rd litre of cleaner and retest.


Should all the above fail, what else should get the garage to attempt?


Look forward to replies


Eamon

I doubt that any petrol on sale in the UK would cause emissions failure

jimbo6977

You could "rinse and repeat" with yet more fuel additives and high-grade fuel (BP Ultimate or whatever). Other than that, deliver it to the test station nice and hot after a long run and make sure they test it right away.

AdrianC

Jumblebumble wrote: »

I doubt that any petrol on sale in the UK would cause emissions failure

...especially in a diesel engine...

OP - the smoke opacity is not "subjective", it's measured by the emissions testing machine. The procedure gives plenty of opportunities to pass, and takes the best three consecutive results out of six. For 1980-2008 turbodiesels, the limit is 3.0... or the vehicle-specific limit, as on a sticker applied to the vehicle, whichever is lower. Yours must have a sticker saying 1.5. I wonder how easily it'll peel off?

It's not a particularly high bar, and a best of 3.0 is pretty damn claggy. I know my own 1997 turbodiesel was very close to a fail last year, and the rear view mirror reminds me of that regularly... It may be that you simply need to drive it harder, or it may be that it needs a bit of TLC. "Serviced to the book" will not necessarily cover it.

alan_d

Excessive smoke is usually because excessive fuel is being burnt, often because of an air leak after the MAF sensor.
Check for leaking pipes and intercooler. As suggested above put some quality premium diesel in it, BP ultimate or Shell V-Power - ideally for a few weeks before the MOT !

EdGasketTheSecond

You need to do the long drive just before the MoT, not the day before though it might help a bit. Make sure it is fully warmed up when they retest. Use a premium brand of diesel as suggested.

eamon

Update.


I have now got an MOT on my car. Took it to the garage this morning and done an unoffical test and it passed. Sadly the MOT tester wasn't available until later this afternoon so I had an anxious few hours.


Assuming that I still have the vehicle next year I'll be getting it tested in the preceeding 28 day window instead of waiting until the day before. I had forgotten the implications of failing the emissions test until too late to do much except panic.


Like many motorists I have the right & wrong car. I like the utility, driving position etc. However I don't drive long enough (M Way) distances on a regular basis to let the engine do its thing.



I'm sceptical about the supermarket fuel thing and I've never been able to find any data that would support that line of thinking. On the few occasions that I have filled up with brand name fuel it is possible that the car does perform better perhaps that is something that I should do more frequently.


For anybody else reading this thread and you have an older car irrespective of the fuel type then use the 28 day MOT window wisely it can buy enough time to come up with a solution that works instead of the headless chicken that was me. Oh and don't go to the MOT centre with your car full of fuel. In my head I had visions of calling one of the misfuelling companies, draining the alledged suspect fuel, partially refilling with brand name fuel and so on. Luckily my wallet kicked in and it was a lot cheaper to drive for 3 hours and go through £40 worth of fuel.