S3 Misfiring on cold start up


Registered User
Jun 10, 2013
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North Lanarkshire
Hi All, been a whilst since i posted but could do with some expert guidance before i start doing unnecessary stuff to the S3. I've had the car since May and as far as i know its mapped, otherwise standard. Put it through its MOT and it passed the emmissions tests. Its developed a problem over the past week where on cold start up, it splutters until i rev it slightly but continues to do this for about a minute. When the car heats up it runs OK. Does occassionally surge when on full boost but not badly. Car is my daily run around and does the 8 mile round trip to work and back so not really getting a good long motorway run. I've had all the vac hoses replaced so no boost leaks. Just trying to give as much info as is relevant. Car is due a service. Also last week filled it with Shell V Power insead of my usual BP ultimate which is when the problems started but dont see why this would cause a cold start....... or maybe? You guys hopefully can advise. I'm thinking maybe spark plugs could be fouled? Any other suggestions of what could be a potential cause?
i had this and a new temp sensor sorted it, but get a genuine one as i tried a cheaper pattern part and it still had the problem.

Once i fitted the genuine temp sensor it was all good.
I didn't get any fault codes thrown up unfortunately.

Just the rough running briefly on cold starts.