New MOT testing rules and diesels
 

No doubt by now most members are aware that as from 20th May there are much tighter emission limits coming into force for diesel vehicles.
A lot is to do with later vehicles with DPF systems, but there have been some changes which may well affect our MG Rover diesels.

As an MOT test station, our gas analyser was upgraded last week for the new emissions. We are now holding our breath as to how it will effect the many MG Rover diesels that we test.

At the end of last week, we tested a 75, not for test purposes, to check out a replacement cat we had fitted. We used the new emission rules and we were unable to get the car to pass. Fortunately, the MOT does not run out until Jan 2019, so the only action we took was to offer the owner a diesel fuel cleaner and hopefully that may eventually sort the problem out.


Initially, our thinking was that hopefully if a car fails, with the addition of a good fuel cleaner and a good run up the road, the problem may be resolved,
but this morning we carried out our first official test under the new rules and again we could not get the car to pass.

Before we resorted to the diesel cleaner, we did a T4 test to check injectors and did find a problem with two of them which may have contributed to the failure. We have now removed injectors, cleaned and replaced injector seals
which were leaking and hopefully this will resolve the problem, as well as changing the breather filter which was bad.

Until we have tested a few more diesels, we do not know how problematic the new emission test will be for our cars. We are going to monitor the situation to see how things go, and will be happy to let other forum members know the results of how many cars may be affected and what can be done to resolve any of the problems.

Our greatest fear is that there will be many MOT test stations that will try to write these cars off if they cannot or will not try to get them through the gas test.


Of course, this does not only apply to MG Rover, but could affect older diesels across the board -we shall have to wait and see. Will be interesting to see if our local breakers start getting more diesels in for scrap in the coming months!

Are the required figures lower than when the car was new? If so I don't see how they can enforce that as surely a vehicle can only meet the standard that it was designed to?

Facelift CDTI models are 1.33, they can’t expect to change these limits, new analyser or not, that limit should still be the same
Mick

We were talking about this at the last nano, and preface lift CDT are 1.00 and may struggle if not in tip top condition as well as the CDTI as you say 1.33 therefore it is best to make sure before your test, change the PCV filter, Air filter, maybe the oil, & it's oil filter, maybe now combining your yearly service around your MOT time.

Drop in some diesel cleaner at the same time, then give it an Italian tune up 30 minutes before you get to the MOT station I have always done this anyway.

It will be good to follow this thread to see how the OP gets on over the next few weeks and months.

Is that on the opacity test? Mine only just struggles to get in at under 3.00

I should imagine this being a problem for badly maintained cars, or cars with a "no smoke, no poke" type remap.

After a bit of thought about this over the weekend, I ran the ZT up to Lion Garage and had their tester Martin put it on their new gas analyser, and there was no issues with it at all, bearing in mind this is a car in tip top mechanical condition.

I then substituted the ECM in a hot swap for an ECM programmed with a Tom Force "MAFless" tune, same car, same operating conditions exactly if you bear in mind it takes me less than 30 seconds to exchange one ECM for another.

The result was a spectacular fail :(

It will be interesting to see how a lot of the cars fare in the coming months.

Brian :D

+1 for Steve (Arctic)

My facelift has a plated limit of 1.00. Passed last year at 0.89 l/m. This year 0.82 l/m.

Does not give much room to pass.

I popped into my MOT tester today to book an MOT for next week. He was telling he has tested 5 diesels today and 4 have failed the new test :eek:. 2 are booked in for some work but the other 2 will probably be scrapped as he reckoned the owners were thinking of getting petrol cars anyway and they were quite old.

I wonder how many diesel powered cars will be scrapped this year because of the new MOT?

He was also telling me he has failed a car because of no reversing lights and another because of an engine management light.

I can see this being the beginning of a cull of old bangers, not before time either.

No one with a well cared for car will have anything to fear, the MOT test even in it's new format is still a basic test of roadworthiness.

I had to chuckle earlier today when the car presented at the testing station I had the ZT emission tested at, failed on a bald tyre, inoperative screenwash and split wiper blades......it's first MOT.

Not everyone treats their car like a family pet, to some people they are a means of A to B and nothing more.

Brian :D

And there was me thinking the changes only affected later model Diesels with DPFs fitted.

Another thing I have just spotted.

Another significant change occurs if a car fails its MOT for something considered dangerous. In that case, the owner risks a £2,500 fine and six penalty points if they drive away from the testing station even if the car’s MOT still has a few days to run. It means dangerous failures will in effect have to be rectified by the testing garage – with some mis-selling likely as a result – or be towed to another garage, with the extra expense that would entail.


Understandable but choose your MOT centre with care as this could give any wide boys in the game an easy way to drum up work.