I have a 172 cup ph2 and when driving it today it seemed slighty stuttery and seemed down on power then it disappeared for a while and came back and went again. I tried booting it to see if it just wanted a good clear out but then started hearing a strange noise from engine. When i got home i opened the bonnet and put the key in and turned it so the dash lights came on and i could hear a mix of a ''hum and whistling'' noise coming from around the engine battery side. I am rubbish with cars and wondered if anybody else had had this problem??????????