Seat Arona failed first MOT

sevenhills

35har1old said:

The wrong oil can clog the dpf which would increase the emissions 

Since the garage has admitted that is what has happened, maybe the OP needs to put a claim in?

chrisw

There's no way the mechanic would know the wrong oil had been used at the last service. It can be determined forensically but that would take time and money.

Barkin

chrisw said:

There's no way the mechanic would know the wrong oil had been used at the last service. It can be determined forensically but that would take time and money.

Agreed. The only possible clue would be if it was specified on an invoice. 

SteveJW

facade said:

I'm guessing it is petrol if it failed on emissions, diesels only have to pass a smoke test, a blocked dpf would push the smoke up though.

Diesels registered prior to 1980 only have to pass a visual smoke check

After that date they have to pass emission tests and the limits vary by year

Lots of misinformation on the net

See gov.uk website for details

facade

SteveJW said:

facade said:

I'm guessing it is petrol if it failed on emissions, diesels only have to pass a smoke test, a blocked dpf would push the smoke up though.

Diesels registered prior to 1980 only have to pass a visual smoke check

After that date they have to pass emission tests and the limits vary by year

Lots of misinformation on the net

See gov.uk website for details

But it is still a smoke test, just done on a machine and called "opacity", they don't test gas emissions like on a petrol.

ROY47

But it is still a smoke test, just done on a machine and called "opacity", they don't test gas emissions like on a petrol.

Sorry but you are wrong The car that failed comes under new rules

https://www.driving.co.uk/car-clinic/guide-new-mot-test-changes-including-tougher-diesel-emissions-limits/

New Diesel MOT Emission Rules

Since the EU Roadworthiness Package of May 2018, it has become a lot easier for diesel cars to fail their MOT. The level of nitrogen oxide (NOx) and carbon monoxide (CO) that diesel engines produce can have a detrimental impact on the environment and, consequently, the EU have put restrictions on the level of diesel emissions that your car can release.

The UK have mirrored this so currently, to pass your MOT, your car's MOT emissions have to fit specific criteria.

In order to pass your MOT, your vehicle must adhere to a set of MOT emission rules. The MOT emission test rules in the UK state that:

• Visible smoke must not come from the exhaust of your car
• The Diesel Particulate Filter (DPF) must not have been removed or tampered with.
• An engine management light - the light that signals there is a problem with the emissions system and/or DPF - must not be displaying

This bit .....

• The emission restrictions for diesel engines must not be exceeded. The emission restrictions are as follows:
  • CO limit of 0.50 gm/km
  • NOx limit of 0.25 gm/km
  • A combined HC and NOx limit of 0.30 gm/km
  • PM limit of 0.025 gm/km.
  
  
  I know it's correct because my Fiesta diesel was close to failing because of emissions . I was told after to drive it on a damn good run on motorway
  

tedted

(a) Smoke opacity levels exceed the manufacturer’s specified limit	Major
(b) Smoke opacity levels exceed default limit	Major

its a smoke test just  phrased differently

ROY47

its a smoke test just  phrased differently

no its not , nothing to do with smoke test it's emission level

The emission restrictions for diesel engines must not be exceeded. The emission restrictions are as follows:

• CO limit of 0.50 gm/km
• NOx limit of 0.25 gm/km
• A combined HC and NOx limit of 0.30 gm/km
• PM limit of 0.025 gm/km.

tedted

so your saying the dvsa are wrong?

ROY47

 I'm saying my answer is correct  did you read the link I posted ?

https://www.driving.co.uk/car-clinic/guide-new-mot-test-changes-including-tougher-diesel-emissions-limits/