nct emissions failure

monara

Any idea on how to reduce emissions for nct?

Murt2024

Did you have the engine up to temperature when brought to test centre. Usually half way point on the needle. Diesel or Petrol?

monara

Petrol. Would it help to drive it in 2nd gear for half hr before test?

greasepalm

Your not giving us much to go on like what type of car it is , do you you do short journeys or motorway driving as that is good for blowing the cobwebs off it.

Does car get a good service or hoping it gets through the test.

qb123

https://www.boards.ie/discussion/2058407163/nct-emissions-failure

Get the car serviced properly so that it doesn't pollute the air that others have to breath in. The emissions test exists for a reason, it's not there to be gamed.

Murt2024

Dipetane in half tank of fuel and drive it normaly until retest, with a few more revs than your used to when you can. No harm then 2nd of 3rd gear for 20 mins before the test as well then with Dipetane still in the tank.

greasepalm

No to Dipetane as it takes a long while to work and is not an instant cleaner. Taxis use it.

User1998

Did you fail?

Murt2024

https://www.boards.ie/discussion/comment/123379934#Comment_123379934

Huh?

Lenar3556

What emissions parameter did it fail on? Can you post the results for CO, HC & Lambda.

JimmyChew

Same boat yesterday. 1.50 limit I came in at 1.71. Diesel car 1.6.

Guilty as charged in driving like miss daisy. I'd rarely get up over 2 or 2.5k Revs. I added a red X and will do another before retest later this week. As advised here also I'll give her a bit of shoe and up the revs day of test. Fingers crossed as i need a pass on this one.

I felt the boys in the test gave it an awful lot of revs during the test i heard her screaming. I get it but can't say i've heard it whine like that in past tests. 0.300 last year's test.

greasepalm

https://www.boards.ie/discussion/comment/123379940#Comment_123379940

Worked in a garage for 40+ years and got to know it takes time for Dipetane to clean the system out.

Plenty of other things that would work better and faster when going for nct.

greasepalm

https://www.boards.ie/discussion/comment/123380025#Comment_123380025

You bought a diesel for the wrong reason as they must get motorway driving to keep the emissions down .

Plan to do a good run on the motorway and hope that Redex works as should remove the crap built up in the exhaust.

NCT were trying to do a burn to see if emissions would drop down , slow and careful dont work for the NCT.

eronayne

it would have screamed as part of every test.

Part of the test for a diesel is to bring the engine up to the redline. A trick in the past was to retard the mechanical fuel pump to reduce the smoke. The rev test would fail if the engine found not reach 75% of the indicated “redline”

best best for a diesel as others have said is to print it for a good run before the test. Also make sure your air filter is clean. Less air into the engine more

Black smoke out the back.