Nct emissions fail

colinjp

Hi , I have a ford focus 2000 1.4 Zetec 138000m which has failed nct on high emissions.

Oil temp - 81c

Low idle
Co 3.23%
HC 1455 ppm

High idle
Lambda 1.30
Co 0.38
Hc 511

I had changed oil, oil filter, air filter, checked spark plugs (clean + gapped correctly to 1.3) added redex after fail and redid emissions test which failed again. Also got lambda checked and was told it was reading ok. (Only pre cat lambda on car)

Have had to top up oil every few months and no leak so think it's burning oil.

No engine management light coming on and car is driving well with no loss of power, maybe slight increase in fuel comsumption. Did Compression test, read :
Cylinder 1 - 190
Cylinder 2 - 200
Cylinder 3 - 180
Cylinder 4 - 180

Only other things are temp gauge tends to fluctuate a lot on the cold side but never goes above halfway, and also speedo needle randomly drops for few seconds(with drop in volume of radio) then returns to normal.

Any ideas would be greatly appreciated !

Kind regards

dh0011

there are a few previous threads on NCT failures becaues of emissions. Have a look. Your values arent just barely failing so running dipetane through the system probably wont make it pass.

Did you try driving the car like you stole it before the test (italian tuneup)?
Is there anything else wrong with the car (something not tested in the NCT)?

jimgoose

Hmm. I suspect a leak somewhere in the exhaust, upstream of the lambda sensor.

debabyjesus

The thermostat could be shot if temp gauge is dodgy...might lead to overfuelling and high emissions. Oil temp for the test could be higher than 81. Id sit in the car park holding it at mid revs to have it as hot as possible before the test

colinjp

dh0011 wrote: »

there are a few previous threads on NCT failures becaues of emissions. Have a look. Your values arent just barely failing so running dipetane through the system probably wont make it pass.

Did you try driving the car like you stole it before the test (italian tuneup)?
Is there anything else wrong with the car (something not tested in the NCT)?

Thanks for reply, don't know if there's anything else wrong- cars driving well,

Took a drive up m50 before 2nd emissions test so engine should have been warm and clear of any carbon deposits, il check the exhaust for leaks and test the thermostat

dh0011

Are there any warnings on the dash?

colinjp

dh0011 wrote: »

Are there any warnings on the dash?

No no warnings and no engine management lights

dh0011

Maybe the oil burning might have something to do with the emissions so. You might need major engine work to get it to pass or even swap the engine. Might be worth taking it to a good garage and asking them to have a look though.

colinjp

dh0011 wrote: »

Maybe the oil burning might have something to do with the emissions so. You might need major engine work to get it to pass or even swap the engine. Might be worth taking it to a good garage and asking them to have a look though.

Ye that's my worry, if it's major oil ring or piston ring damage itl cost a lot to repair - prob more than the cars worth !
The cylinder compression seems ok though so hoping it's something else

emeldc

Spray full tin carb cleaner into throttle body at high revs. Add bottle of injector cleaner to about 25ltrs fuel and drive the nuts off it down the M9 to KK. Repeat for the return journey. If that doesn't help go to post 3!

George Dalton

jimgoose wrote: »

Hmm. I suspect a leak somewhere in the exhaust, upstream of the lambda sensor.

I agree. The flexible section of the downpipe is a common spot for them to leak.