Well, I fell the need to get involved in this thread because my random idle is strating to bug me. Tonight for example, on cold startup it went straight up to 1500rpm, which is fine, 15 mins later its at 1100 rpm, it then stays that way for the next 20 mins, then all of a sudden, you pull up at a set of lights and the revs drop to the 500-600 mark, but by this time, im virtually outside my house and about to park the car in the garage, surely, it shouldn't take that long to warm up, especially as I was giving it large on the deserted motorway on the way home, I thought maybe a good hard run would clean it out a bit.