Emissions MOT Fail

[mechie]

My clio has been off the road for around 3 months now and was planning on being back behind the wheel a few days ago but unfortunatly my car failed its MOT. It failed on a few things but are easily repaired my big problem is the emissions carbon monoxide content after 2nd fast idle excessive! The readings were .....

Fast idle test : CO%vol : Max Limit .300 actual value .636 FAIL
Second fast idle test : Max limit .300 actual value .659 FAIL
Natural idle test : Max limit .500 actual value .200 Pass

Lamda and HC both pass

I never gave it a massive run before mot becuase my car isnt taxed or mot'd

The garage that told me they would do the mot actually send the car away to another local garage and they do the MOT but the other garage dont pick my car up straight away so the car is cold by the time they take it... im not happy with this at all but ive allready payed for the mot so a retest is free. What can i do to make sure it passes?

​Thanks

 

[The Fatty]

My 1.2 used to fail spectacularly unless it was properly warmed up. I would be making sure the engine is up to temp at drop off, and make sure you tell the garage to make sure its up to temp before doing the emissions tests. Place I used to get my MOT done use to just leave it on the fast idle until it passed the test, maybe they could do the same?

 

[Chi]

You would think the garage would know this FFS!!!

 

[Tony Hunter]

You would think the garage would know this FFS!!!

​They don't care.

 

[mechie]

like i said the garage that i take it to have another garage pick it up so the cars cold by the time they do. can i request them heat the car up?? also ive realized i forgot to change my airfilter before mot and its black.. Possible cause?
​

 

[Beasley Clio182]

like i said the garage that i take it to have another garage pick it up so the cars cold by the time they do. can i request them heat the car up?? also ive realized i forgot to change my airfilter before mot and its black.. Possible cause?
​

Would replace it regardless ! If its been sitting and cold on the test it will fail ! Get it stinking hot before the test , even if you have to sit a rev it ! Just get it warm before you leave for the test centre and make sure it's given a good booting !

Im a mot tester and we should warm them up but a lot don't !

 

[The Fatty]

leave a note on the dashboard saying something like "Please make sure the engine is up to operating temperature before running the emissions test. This takes about XXX minutes on 3KRPM. Failure to do this will result in the car failing the emissions test. Thank-you" - replace the XXX with the number of mins it takes to get hot at 3Krpm.

 

[ben lee]

if they done a fast idle test and 2nd fast idle test then the car will be up to temp.
looks like a faulty cat from the readings.

its when the test centre only does a BET test that it might not be up to temp.

 

[Tony Hunter]

Leaving the car to tick over to get to temp, is not the same as giving it a good run to get it warm.

 

[ben lee]

before starting the test the car should be warmed up oil over 80 deg or temp showing hot or fan cutting in before the test is started. if a car fails the BET test then you test it on a full cat test. then if it fails 1st fast idle test of a full test then the computer gives you 3-5min warm up at fast idle before starting the 2nd test cats get plenty of time to warm up.

also if the engine is not up to temp it usually will also fail on high hc and lambda out.

 

[Tony Hunter]

before starting the test the car should be warmed up oil over 80 deg or temp showing hot or fan cutting in before the test is started. if a car fails the BET test then you test it on a full cat test. then if it fails 1st fast idle test of a full test then the computer gives you 3-5min warm up at fast idle before starting the 2nd test cats get plenty of time to warm up.

also if the engine is not up to temp it usually will also fail on high hc and lambda out.

In practice, a lot of the above just doesn't happen I'm afraid.