Nct emissions - fail on high CO

theShire

Hi all,
Just had nct on my 1997 Toyota Levin.
Only failure was high CO reading @ high idle, any advice?

Low idle:
CO: 0.04% (fail above 0.50%)
HC: 48ppm (N/A - fail above 0ppm)

High idle:
Lambda: 1.00 (fail outside 0.97-1.03)
CO: 0.37% (fail above .30%)
HC: 62ppm (fail above 200ppm)

Engine temp 101C

scamalert

is it burning oil ?

kavanada

They're good figures for a fail. Good chance of passing.

What was the engine temperature on the sheet?

Does the engine temperature gauge on the cluster read the normal temp after a few minutes? I had a stuck thermostat that showed up with a CO of 0.47% with all other figures in the normal range.
Got it fixed and it's last NCT read 0.10%.

When were the current spark plugs and air filter put in?

Failing that, I would say dipetane and a 3rd gear run.

theShire

scamalert wrote: »

is it burning oil ?

I topped up the oil by about a litre during the week but don't think its burning much.
Last oil change was done for nct in June last year.
Car has only done about 2500km since I use it to commute to work locally every day.

theShire

kavanada wrote: »

They're good figures for a fail. Good chance of passing.

What was the engine temperature on the sheet?

Does the engine temperature gauge on the cluster read the normal temp after a few minutes? I had a stuck thermostat that showed up with a CO of 0.47% with all other figures in the normal range.
Got it fixed and it's last NCT read 0.10%.

When were the current spark plugs and air filter put in?

Failing that, I would say dipetane and a 3rd gear run.

Last service was done June last year for NCT - plugs, air filter and oil.
I've only covered 2500km since.

Temp gauge seems to read OK, normally up to temp after a couple minutes of driving.

I'll take a look at the air filter again because its a cone filter so may have collected some dirt.

kavanada

theShire wrote: »

Last service was done June last year for NCT - plugs, air filter and oil.
I've only covered 2500km since.

Temp gauge seems to read OK, normally up to temp after a couple minutes of driving.

I'll take a look at the air filter again because its a cone filter so may have collected some dirt.

Ok. With that little mileage, you probably do stop-start short journeys followed by laying it up for a few days? Hopefully the dipetane and good run up the motorway should clear it. You've probably also topped up the fuel tank 3-4 times?

What was the HC ppm?

theShire

kavanada wrote: »

Ok. With that little mileage, you probably do stop-start short journeys followed by laying it up for a few days? Hopefully the dipetane and good run up the motorway should clear it. You've probably also topped up the fuel tank 3-4 times?

What was the HC ppm?

Yep, very short journey - about 10minutes each way Mon-Fri, then parked up at weekends.

I added dipetane during the week but maybe it didn't have long enough to work its magic.
NCT is not out-of-date until end of the month anyways so I’ll give it a few good runs with dipetane and put it through again.

HC was 62ppm at high idle (i've added details to first post)

Really thought the car would fail - its 18years old!
But with it only being slightly out on emissions its worth trying to sort it out.

Seweryn

theShire wrote: »

Really thought the car would fail at this stage - its 18years old!
But with it only being slightly out on emissions its worth trying to sort it out.

Cars don't fail NCT on age, they fail on condition.

With those figures you are easily to pass with a good run before the test.

theShire

Seweryn wrote: »

Cars don't fail NCT on age, they fail on condition.

Agreed, didn't want it to fail, just surprised it didn't need anything else.

Last year it failed on the spoiler brakelight, few of the LEDs had blown.

Great car, I've had it 10yrs and its still going strong

kavanada

Let us know how you get on.