MOT fail diesel emissions

[kit]

Just got me fail from the garage, diesel emission too high on their new machine Any one any suggestions? I know it should be in Technical but I am desperate for a solution.

[Ian Hulley]

Just got me fail from the garage, diesel emission too high on their new machine Any one any suggestions?

Tell them to use their OLD machine ? Sorry I'm being facetious

Good luck. Ian.

[kathyshack]

moved to technical, as it is a technical question. People do read technical so hopefully someone wil beable to help.
kathy

[gally]

try a diesel treatment . put in a full bottle with a fivers worth of diesel.
drive the van hard for a few miles,have it nice and warm before test.
worked on an old golf for me. it also worked for lots of other people i know.
gally

[fullsunian]

Like gally says, put some diesel treatment it with a low tank of diesel then take it for a good hard thrash up the road just before you take it back for a retest, don't be suprised to see clouds of black smoke behind you lol. Making sure its nice and hot when the tester tests it. If it don't pass after that then there is something wrong with it....

[marble]

silly question , but fuel and air filters (fuel is often forgoten) and engine oil. if it struggles after a thrash take out the air filter. Ive got a bodging aprentaship behind me.

[Rozzo]

take the air filter out and turn the fuel down. not sure where the fuel screw is but some dervil expert will be along shortly i'm sure.
good luck

[vwjon]

heres a really good tip, (a little naughty so you didnt hear it from me) if the injector cleaner doesnt work, you will need 1/4 tank of diesel and 4litres of NEW veg oil, go for a drive this will 1, clean the engine, 2 mix the veggie and diesel.

veggie burns with NO hydro-carbons, this is what the machine picks up. my passat used to run veg oil (legally) only using 5% diesel i loved MOT time the macine used to say hydro-carbons and particulates 0% please insert probe! the had to pass it!!!

[JamesT25]

i agree with vwjon,

i run my bora on biodiesel, should be able to find a supplier nearby who sells, 210k miles on my bora and emmisions are none existent its good to see the testers face when the slip prints out!!

Just thought i'd stick my oar in

[kit]

Does anyone know if the advance cold start lever will make any difference?

One tip I had was to fill the fuel filter with injector cleaner just before they start it so it is running on that rather than DERV, I am to say the least a bit concerned as I do not want to have to fit anew engine as yet.

[andysimpson]

heres a really good tip, (a little naughty so you didnt hear it from me) if the injector cleaner doesnt work, you will need 1/4 tank of diesel and 4litres of NEW veg oil, go for a drive this will 1, clean the engine, 2 mix the veggie and diesel.

veggie burns with NO hydro-carbons, this is what the machine picks up. my passat used to run veg oil (legally) only using 5% diesel i loved MOT time the macine used to say hydro-carbons and particulates 0% please insert probe! the had to pass it!!!

Machine reads smoke density only and not levels of any gases

[andysimpson]

Additives won't do any good, just a waste of money. The best thing is go down road in 2nd gear and keep accerating upto as fast as it will go in that gear and then slow down, keep repaeting that for about 2 minutes and it should pass unless there is something wrong. As above check air filter.

[wee bugger]

Like gally says, put some diesel treatment it with a low tank of diesel then take it for a good hard thrash up the road just before you take it back for a retest, don't be suprised to see clouds of black smoke behind you lol. Making sure its nice and hot when the tester tests it. If it don't pass after that then there is something wrong with it....

mine failed on emissions too...the mechanic did this and it passed (his receipt actually says "added diesel treatment and took for hard run" )

[barney]

Biodiesel is the (short-term) answer.

Filled my smokey old van with it before recent MOT and it flew through the emissions test.

The year before with a tank full of normal diesel it had only just scraped a pass, with a lenient, light-footed tester (apparently).

....smells of donuts too. Bonus!

Barney

[HarryMann]

Turn the fuel screw down a bit as well, if in doubt