MOT Failure on Hydrocarbon and CO2 level

Dec 19, 2006 26 Replies

I recently MOT'd my car which is a 2001 saxo 1.1 it passed everything but the exhaust emissions. Firstly it failed on the exhasut emissions carbon monoxide content at idle excessive The secondly on the Exhaust emissions hydrocarbon content after 2nd fast idle excessive



So i had been told to change the lambda sensor which i did so i then took it for my free retest however it failed on the same things



Has anyone got any ideas as to what it could be all will be appreciated thank you



Was it properly warmed up, is it able to properly warm up?

What were the figures??

Tim..

The latest figures were: co2 level 0.64% should be 0.30% Hydrocarbon level 234 should be 200 second fast test

0.63 314 at idle co2 was 0.54 should have been 0.50 max it does normally warm up fine i had to drive about 5 miles to get to the place so it is able to warm up and it was warmed up cheers

Tim.. wrote:

Your emissions figures point to an un-warmed up car, although they could be caused by other reasons.

5 miles through traffic does not constitute a hot enough cat, although the engine should be hot enough. I dont think there is a temp gauge on a Saxo, so get a thermometer and measure the water in the expansion tank to make sure its at 90 or so deg C. A good fast run immediately before the test would be a good idea too.

Is there any sign that the car is using more fuel than normal and has it been serviced recently?

Tim..

Coady ( snipped-for-privacy@hotmail.com) gurgled happily, sounding much like they were saying :

Five miles isn't warmed up.

** DONT ** open the expansion tank when its hot, especially at that temperature !!!

Reg.

what does the oil temp say on the print-out ? as it failed the BET test a full cat test would have been performed & the oil temp would have been taken.

Lin Chung (lin.chung@the Water Margin.com) gurgled happily, sounding much like they were saying :

No, it doesn't.

The water might, but the oil most certainly won't.

Coady ( snipped-for-privacy@hotmail.com) gurgled happily, sounding much like they were saying :

Get your priorities sorted. If you can't afford to maintain your car properly, you can't afford to drive. Servicing is as non-optional as MOT or insurance or tax disc. Driving a relatively new car into the ground because you "can't afford" to get it serviced is a false economy, and WILL cost you more. Spend less on Xmas.

Yes.

Service it.

Service items.

the minimum required for a MOT cat test, so it was within temp range.

( snipped-for-privacy@hotmail.com) gurgled happily, sounding much like they were saying :

IF that temp was actually sensed, not bypassed and entered. One hell of a coincidence that it's bang on.

no coincidence, when the machine reaches 80c you hit the " its warm enough, carry on with fast idle button " it can read over 80c & print it if you want, but i hit it at 80c.

Lin Chung (lin.chung@the Water Margin.com) gurgled happily, sounding much like they were saying :

You've never driven a car with an oil temp gauge, have you?

Oops....the masses 'are' the almost the same. Not awake yet!

The mass of the water coolant in a typical engine and that of the engine oil is almost the same. The specific heat of water, however, is 2.2 times greater. So, by the time water reaches 90ºC, oil temperature should be well over 90ºC.

"...The specific heat at constant pressure for the water and the oil are Cp-water = 4181 J/kg ºK and Cp-oil = 1900 J/kg ºK respectively..."

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Part B, 1/2 down the page).

I'm not sure where your logic is going wrong, but I can assure you that practical observation means it is *very* wrong!

Chris

Okay. Should be interesting to listen to an explanation of the facts not harmonizing with the theory.

first step is a service. if it has one then remove the giant exhaust box and replace with the right item, get it hot and take it for its test.

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