Emissions

[aworsley4]

Hello all, been a while since ive posted but ive had a while of trouble free motoring up until my MOT. I have a 1999 6N 1.0L petrol polo. It failed its MOT yesterday with its CO through the roof. Since it had a new waterpump and cambelt last year the engine temp never reaches 90 degrees unless the cars stationary for over twenty mins. I think its the coolant temperature sensor which is faulty telling the engine its warm when its cold and vice versa so the engine is throwing in excess petrol to compensate when it doesnt need it so my emissions are high (and mpg is low :sad2. Anybody got any other theories.
p.s. my rear drums are completely seized. unsure if this is a common problem or not but its used everyday which is why i was a bit confused as to why that happened.

Any help much appreciated

 

[PedroS]

i would bet in one of these:
water temp. sensor (as you said) , thermostat valve , air filter , sparkplugs , oil and filter ,petrol filter and a good highway run...
or just do them all.

 

[pgarner]

coolant sensor will hit 90 then go back down and up.
thermostat could be jammed open meaning the coolants being over cooled.
dirty maf

or the fact the engines small and quite old now it could be burning oil causing the higher emmisions

rear drums are probably full of crud

 

[aworsley4]

well before its mot it had new fuel+oil filter, new oil, plugs and leads. I doubt its the thermostat as its had 3 new ones in the last 2 years and I know exactly how it behaves lol when its dud. I replaces the coolant temp sender and its runnin like a dream so hopefully that will solve the issue. It no longer sounds like a spitfire when I start it up in a morning (which I am a bit sad about but my wallet isnt). Gonna get it checked again and see if thats improved things.

 

[PedroS]

cool

let us know if its sorted.

 

[Prince]

Get a diagnostics done. It may be the lambda.