temperature sensor question

[pitchy]

as ive posted before ive got the light on, codes came back pointing to the o2 sensor, saying heater circuit. i was meant to be buying a replacement front sensor(aum) at the weekend but ive read into something that makes me think it could be something else. im basicaly getting poor mpg and running slightly odd sometimes ( signs of o2) but iv also noticed my temp gauge isnt running at 90 very often, and the guage has stopped working a few times! could this be my culprit? i didnt realise till reading other posts recently that it should sit at 90 if the sensor is working. for the sake of a tenner im gona change it and keep my fingers crossed. does this sound familiar to anybody else?
cheers

[G60GTI16V]

from the amount of posts iv read about this issue sound like it.

[northeast_gti-t]

could well be have you had any error codes on vag com in relation to the coolant temp sensor ?

[pitchy]

it said o2 sensor heater circuit , not quite sure what that means tho? 
the lambda cant be totally shot cos i can get good mpg if i go steady, im under the understanding that when theyre gone you get rubish mpg all the time? maybe wrong? could it also be stat ? i know theyre only cheap but i cant be arsed with dropping the coolant and dealing with air locks etc etc might just drop it off at the garage?

[northeast_gti-t]

it said o2 sensor heater circuit , not quite sure what that means tho? 
the lambda cant be totally shot cos i can get good mpg if i go steady, im under the understanding that when theyre gone you get rubish mpg all the time? maybe wrong? could it also be stat ? i know theyre only cheap but i cant be arsed with dropping the coolant and dealing with air locks etc etc might just drop it off at the garage?

thats the heating element basically to pre heat the tip of the lambda probe when its started up to get it to operating temp quicker i'd take it to a garage if you don't want the hassle but following tims how to guide mate changing the stat is fiddly but easy enough and would save you money 

[topher]

If you have any doubts about the coolant sensor, for what it costs.. i always tell people just to replace it. I doubt it'll solve your issues but it's one more thing to tick off the list.

[northeast_gti-t]

If you have any doubts about the coolant sensor, for what it costs.. i always tell people just to replace it. I doubt it'll solve your issues but it's one more thing to tick off the list.

agreed for the sake of a tenner and five mins work worth doing 

[pitchy]

yeah im deffinately doing it anyway, with the gauge not working at all sometimes points to it bein knackered, do you think the lambda def needs replacing then? last time i tried to change one of these was on my old calibra v6 and it just wasnt comin out! whats this heater element thing, im assuming the lambda will still do its job with that little malfunction? or will it just be not working at all?

[northeast_gti-t]

yeah im deffinately doing it anyway, with the gauge not working at all sometimes points to it bein knackered, do you think the lambda def needs replacing then? last time i tried to change one of these was on my old calibra v6 and it just wasnt comin out! whats this heater element thing, im assuming the lambda will still do its job with that little malfunction? or will it just be not working at all?

i'd also replace your lambda sensor yes as its showing a fault code the heating element is part of the lambda itself just pre heats it not unlike glow plugs on a derv really it will still work but not as efficiently but will just fail eventually at a guess 

[pitchy]

i cant get my head round why it would need a pre heater? surely within a minute it will be hot anyway ?