Hello, I have an Audi A2 and am experiencing a problem with smoke coming from the engine.

When the car is registering 5c or below, and I only drive a short distance, when I turn the engine off, smoke comes out from the bonnet. The smoke has a slight smell to it and it stops after about a minute. It just looks quite alarming, especially when the short distance I've driven is to the petrol station. ..

I've had it in the garage and they can't see anything obvious that would cause it, and can't do anything without replicating the problem, which, by the time I've driven it to the garage won't happen because of the distance.

There is the sound of a fan that kicks in when it hits 5c or below. But I wondered if there's anything really obvious that the garage might have missed.

Thanks