MOT emissions fail.

[cdbe]

My (recently serviced) 2007 Golf 1.9Tdi failed on the emissions yesterday. Managed to get it through today - Wynn's Diesel Clean-up in (a new) fuel filter and a 50 mile caning round the motorway just before the re-test. However, it appears to have barely scraped through - the limit used was 1 and it got 0.97!

I've read on the web that there is a higher default limit of 3 for a car of this age that should be used unless the car has a different plated limit, mine does, on the sticker on the passenger door frame. It's further suggested that if this value is not legible/missing etc then the default limit should again be used. Is this true or has the plated limit already been permanently stored on the "MOT computer"?

 

[Keithmac]

Our 2013 Kuga read 0.1 on last test, your DPF is probably at end of life (Ash loaded).

At the end of the day the DPF is a service item.

3% Co is for petrol cars not on the list iirc, Diesels use Opacity value.

No point moaning at the MOT tester, they're only doing their job and have DVSA breathing down their back to do it properly..

 

[Mottie]

Next time, scratch, remove or paint over that section of the manufacturers plate then they'll have to use the default measurements.

 

[Avocet]

Next time, scratch, remove or paint over that section of the manufacturers plate then they'll have to use the default measurements.

I thought DVSA were wise to that one now, and are insisting on manufacturers' values?

 

[Avocet]

Our 2013 Kuga read 0.1 on last test, your DPF is probably at end of life (Ash loaded).

At the end of the day the DPF is a service item.

3% Co is for petrol cars not on the list iirc, Diesels use Opacity value.

No point moaning at the MOT tester, they're only doing their job and have DVSA breathing down their back to do it properly..

I wouldn't have thought a 2007 car would have a DPF? I think they came in about 2011 or 12?

 

[Avocet]

My (recently serviced) 2007 Golf 1.9Tdi failed on the emissions yesterday. Managed to get it through today - Wynn's Diesel Clean-up in (a new) fuel filter and a 50 mile caning round the motorway just before the re-test. However, it appears to have barely scraped through - the limit used was 1 and it got 0.97!

I've read on the web that there is a higher default limit of 3 for a car of this age that should be used unless the car has a different plated limit, mine does, on the sticker on the passenger door frame. It's further suggested that if this value is not legible/missing etc then the default limit should again be used. Is this true or has the plated limit already been permanently stored on the "MOT computer"?

View attachment 265114

View attachment 265115

I have a theory that unless used at maximum power every now and then, turbo diesels accumulate a lot of sooty, oily gunge in their inlet manifolds, intercoolers, pipes, etc. 30 seconds at max power, every few weeks, gets the airflow up to a maximum, passing through the inlet tract. I think this "drags" the gunge through the system and into the cylinders where it gets burned. Every now and then, I would borrow my wife's diesel. It would smoke like a pig when I booted it the first few times, but would then clean up a bit. Likewise the Freelander that I got given because it had failed its MOT on smoke. A good "Italian tune-up" and the smoke readings dropped right down. Might be worth a try? The trick, of course, is to find a way of using max power for 30 seconds without losing your licence! Max revs alone won't do it. The throttle has to be wide open to get the turbo shoving loads of air in. A steep hill with a trailer on the back works well, if you have either?

 

[Mottie]

I thought DVSA were wise to that one now, and are insisting on manufacturers' values?

No. Unless it is a compulsory item (such as a vin number), it cannot be failed if it is not visible. In the case of a vin number, there is a specific fail for it. The actual wording for emission data on a diesel is:

The maximum smoke level limit will be the level displayed on the manufacturer’s plate; or where there is no manufacturers plate information:
For vehicles first used before 1 July 2008, the maximum level is:

• 2.5m-1 for a non-turbocharged engine
• 3.0m-1 for a turbocharged engine

So, all you have to do is make sure there is no manufacturers plate information visible.

 

[cdbe]

No DPF. Neither does our late 2010 Touran (probably one of the last made without). Unfortunately it does just chug around town so I shouldn't be surprised. I'll be more prepared for it next year - oil and filter change just before, cleaner in a few refuels and an "Italian tune up" before it goes in.
I've heard that little sticker often gets damaged when people trap the seat belt buckle in the door!!

I have heard that removing the air filter for the test helps but it does sound like a desperate measure.

 

[Avocet]

No DPF. Neither does our late 2010 Touran (probably one of the last made without). Unfortunately it does just chug around town so I shouldn't be surprised. I'll be more prepared for it next year - oil and filter change just before, cleaner in a few refuels and an "Italian tune up" before it goes in.
I've heard that little sticker often gets damaged when people trap the seat belt buckle in the door!!

I have heard that removing the air filter for the test helps but it does sound like a desperate measure.

If your air filter is a reasonable quality one (e.g. Mann, Bosch, Mahle) and not absolutely choked full of cr4p, it shouldn't make a difference.

Also, I've never tried it myself, but I know a few taxi drivers ho absolutely swear by the Forte injector cleaner products. Might be worth a bottle of that in the tank before an MOT?

 

[RandomGrinch]

I'm having flashbacks now
My first car, a G reg Metro 1.3L
Drove perfectly on the test drive - I picked it up from the dealer after it had its MOT.
Was absolutely undrivable! I stalled in the middle of a busy city junction and couldn't restart the car.
Turns out the dealers had bent the carburettor piston to get it to pass the emissions check!

 

[Belle427]

Some vag cars had a dpf fitted from 2006 I believe, it’s a bit of a minefield.
A tank of super diesel now and again works well too if you can find it and stomach the costs.

 

[cdbe]

Passed this year!

Costco "premium" diesel with Redex Diesel Fuel System Cleaner Treatment added on each of the last 3 tanks, oil and filter change and FORTE DIESEL EMISSION REDUCER added to a quarter tank yesterday and an "extended test drive" just beforehand - got a fast pass at 0.87!

 

[DiyNutJob]

Not buying this cleaner BS. I once had this MOT guy failing me and refusing to print the emission results saying printer broken. He printed the certificate OK. He said he would let me off for £10, then suggested I buy a £30 magic potion from him. When something like that happens, it's time to find another MOT tester.

 

[Avocet]

Not buying this cleaner BS. I once had this MOT guy failing me and refusing to print the emission results saying printer broken. He printed the certificate OK. He said he would let me off for £10, then suggested I buy a £30 magic potion from him. When something like that happens, it's time to find another MOT tester.

You should actually report such an incident to DVSA. They can take action if someone is accepting bribes. In fact, there's just been a DfT consultation on the future of the MOT testing scheme, video evidence of the test was one item mentioned.

 

[DiyNutJob]

You should actually report such an incident to DVSA. They can take action if someone is accepting bribes. In fact, there's just been a DfT consultation on the future of the MOT testing scheme, video evidence of the test was one item mentioned.

You can prove the cash bribe, how? Then, you have to assume I have nothing better to do.