NCT Smoke test FAILED

gezgblack70

Went down to NCT today and failed the smoke test

They said its at 4.3 / m and the limit is 3.0 /m

The car is a Toyota Corolla 1.4 D-4D , 2005

Just wanted to ask for a right direction, don't have a clue as to a fix.

I've heard of using Dipetane or REDEX(Diesel) and giving the engine a good rev , does anyone know , or have any experience with this sort of thing ?

Cheers for your time

Renegade Mechanic

gezgblack70 wrote: »

Went down to NCT today and failed the smoke test

They said its at 4.3 / m and the limit is 3.0 /m

The car is a Toyota Corolla 1.4 D-4D , 2005

Just wanted to ask for a right direction, don't have a clue as to a fix.

I've heard of using Dipetane or REDEX(Diesel) and giving the engine a good rev , does anyone know , or have any experience with this sort of thing ?

Cheers for your time

Dipetane is your friend. A third of a bottle in the tank, fill said tank and an hour on the motorway.

sumo12

Renegade Mechanic wrote: »

Dipetane is your friend. A third of a bottle in the tank, fill said tank and an hour on the motorway.

+1

gezgblack70

Renegade Mechanic wrote: »

Dipetane is your friend. A third of a bottle in the tank, fill said tank and an hour on the motorway.

Thank you so much for a quick reply , really appreciate it. Just a quick question, should I take her out on the drive the day of the NCT test or beforehand ?

Renegade Mechanic

gezgblack70 wrote: »

Thank you so much for a quick reply , really appreciate it. Just a quick question, should I take her out on the drive the day of the NCT test or beforehand ?

Any time before hand but dont empty the tank before the test. Itll still be improved for a,while after but a vehicle with emissions trouble will be at its best chances with that in its fuel.

mullingar

A 1.4 D4D with emissions @ 4.3 :eek:

Sounds like it badly needs an Italian tune-up with Diputane

mgbgt1978

OP, you didn't leave the car idling for a bit while waiting before the test by any chance ?

Cleveland Hot Pocket

Surely dipetane/redex would only work if you are a little over, not c45% over!
Would be better to find out what the actual problem is

gezgblack70

mgbgt1978 wrote: »

OP, you didn't leave the car idling for a bit while waiting before the test by any chance ?

No, have been driving the car regularly , almost everyday.

mgbgt1978

I was asking if you had the car idling for 10 minutes or more while waiting for the car to be tested.
This will cause a massive build-up of soot and sometimes the smoke test can even go off the scale (even if the tester gives it a few decent revs).

Anyway, as others have said, a dose of Dipetane and a hard thrash on the Motorway (almost flat out in 2nd and 3rd for a few miles) should burn off the excess carbon.

visual

When was the car last serviced
and was the air filter changed ?

Renegade Mechanic

Oh yeah, definitely ensure its been serviced with the filters changed and a quick scan! Our own failed at 4.0 exactly. 2.8 after the treatment. It was a 1.6 HDI, highish mileage (near 190k) and was driven quite slowly and easily by its owner so the motorway spin was very beneficial.

Citroen2cv

My car failed the smoke test a few weeks ago. An alfa 159 1.9jtdm. Smoke reading was nearly 6. I had totally forgot to give the car a good hard drive before the test.

Threw half a bottle of dipetane in the next full tank, drove the bag out of the car before the retest. Pass!!!! Smoke reading was 0.5.

ZiabR

gezgblack70 wrote: »

Went down to NCT today and failed the smoke test

They said its at 4.3 / m and the limit is 3.0 /m

The car is a Toyota Corolla 1.4 D-4D , 2005

Just wanted to ask for a right direction, don't have a clue as to a fix.

I've heard of using Dipetane or REDEX(Diesel) and giving the engine a good rev , does anyone know , or have any experience with this sort of thing ?

Cheers for your time

Like me, you most likely don't drive the car hard? My Passat this year failed on smoke of 6.8 which I could not understand. I was told to take the car out, get the engine up to temp and gun it a few times in 2nd and 3rd. Sure enough when I did this the amount of smoke that came out the back was unreal. Went back for my retest and the car passed with 0. something, (cant remember the exact figure) and your man doing the retest said, clean car when handing me the keys.

Essentially, all the low rev, low gear driving causes soot etc to build up in the exhaust. When in the test centre the first time, your man was reving car like mad blowing all this soot into the system which gave the reading of 6.8.

ION08

02 Audi A4 1.9 TDI with 140k miles, remapped to 180bhp , passed with 0.00 on the smoke test. Tester couldnt believe it

mullingar

ION08 wrote: »

02 Audi A4 1.9 TDI with 140k miles, remapped to 180bhp , passed with 0.00 on the smoke test. Tester couldnt believe it

Have you dyno proof of 180hp?

I seriously doubt you could get 180hp on that old 1.9 engine and keep it reliable, but willing to eat humble pie if you can prove it!

Smoke test only checks for particulates in the emissions, no gas analysis.

ION08

mullingar wrote: »

Have you dyno proof of 180hp?

I seriously doubt you could get 180hp on that old 1.9 engine and keep it reliable, but willing to eat humble pie if you can prove it!

Smoke test only checks for particulates in the emissions, no gas analysis.

Yeah true, but the point i'm making is that 0.00 from an "old" remapped TDI is pretty impressive

Heres my dyno sheet:

PBWXFORD

Out of curiosity who remapped your car?

ION08

PBWXFORD wrote: »

Out of curiosity who remapped your car?

Joe POWERRRRR

Running the remap for about 20,000 miles without a single hiccup

PBWXFORD

I had a fair idea it was him was just making sure!

ION08

PBWXFORD wrote: »

I had a fair idea it was him was just making sure!

Are you looking to remap yours?

PBWXFORD

I already have my Vectra tuned fairly well, 246bhp I wont intrude on this thread with details but if you have a look at my other posts you'll see why I asked or I can give you a pm!