engine fault

[Themoog]

The wife came home last night and said the car was playing up. This morning it started ok but struggled to idle and was hunting badly for the first 20-30 seconds. The fan at the front was on full chat as well- something I have never noticed before. There was also smoke/ steam coming from exhaust and a smell of burning oil.
After 30 seconds it settled and ran ok.
Any ideas? I'm pretty good with me mechanics but its always good to get initial ideas from members on here. Thanks.

[zollaf]

any idea what car it is, or even better what engine ??

[Themoog]

Oh yes sorry.. 3.0 v6 2003 a4 cab.

[Themoog]

I put my generic code reader on it and I got p0116 engine coolant circuit (or something like that). Could it be that the signal is telling the engine it is warm when it I actually cold- hence fan coming on at full chat at start up? That's my theory.. I actually bought a coolant sensor a while ago as I read somewhere that it is a common fail. Comments please.

[fourringsrus]

Coolant temperature sensor will do exactly that, tell the ecu to enrich or weaken the mix etc, so your on the right track in my opinion

[Themoog]

Fixed. New sensor on this morn. Bit difficult to get to but not too bad.

[fourringsrus]

Top man,I hope you used genuine and not a cheap alternative