[Engine] MOT failure on emissions.

[Keith Downie]

Hi all.
Just joined forum,so hi everyone.
I have a 2011 Berlingo 1.6hdi van.Had it over 5 years now,and it's been fantastic. 100,000 miles. Changed oil& serviced regularly. Mostly local decorating jobs, occasionally on motorways. Problem is it's just failed Mot on emissions! Can't find out whether it has a dpf or not,but either way not sure what to do. Everyone says give it a trashing. Hopefully not a new Cat needed. Any ideas would be appreciated.

[geoff]

Thrashing isn't really needed but it is worth giving the fuel tank a very heavy dose of fuel cleaner ie a full bottle rather than a portion of one and then give the engine some work to do - get some motorway driving done and when on A roads try and work the engine through the gears rather than just running on torque curve which is the usual / easiest way of driving. Try and get a few gallons through the system.
A new fuel and air filter is always a good datum especially for an MOT.
Beyond this you may have an issue but try it anyway and see how your emissions retest goes, by the way get the engine nice and hot before the MOT

" Pressing on and making significant progress down the road " rather than thrashing is how I try to describe it.

[Romahomepete]

It is worth planning the new filters and oil plus the fuel additive a few weeks before the MOT and a good run at speed on the motorway to clear everything out.

Peter

[Sol]

You probably won't have a DPF yet, 2012 was the start of those but the solution depends on what exactly it failed on....noX or CO etc? Incomplete combustion, burning a bit of oil, cat being depleted can all cause fails. It does have a cat btw.

[cancunia]

You can check if you have a DPF via the VIN.
See the link in this post from JJ9
https://www.berlingoforum.com/thread-170...#pid109715

As regards the thrash, aka Italian Tune Up. I believe that it can make a difference, Saskak posted a thread about this recently, but if you do have a DPF, it's probably worth checking that it's had a regen recently before high revving for long periods.

[saskak]

Diesels are only tested with an opacity test, i.e how translucent are the exhaust gasses and reported by the MOT as absorption coefficients. Have a look at the MOT failure paper what the absorption coefficients are.

I never believed in the "Italian tune up", but now I do. Despite working my 1.6HDi without DPF quite hard (~3,500rpm) for ~1h before the MOT, it failed on emissions. The technician took it around the block for literally 5-7min and passed straight away. His Italian tune up must have been a lot harder than mine, someone reported that it needs to be 4,500rpm. Here is the thread with all the absorption coefficient numbers: https://www.berlingoforum.com/thread-18853.html