Hi my partners mk 4 ibiza has developed an annoying noise over the past couple of days. Basically when you are sitting with the car idling there is a rumbling noise from the back of the car! Which does go away when you rev it slightly. At first I thought it sounded like a fuel pump but I'm now thinking if it's exhaust related! The car still drives as it normally does but has this annoying grumble of varying loudness at idle. Tonight when u got out the car you could hear quite an audible ticking noise whilst on idle coming from underneath the car which disappeared as soon as you switched it off. I'm going to have a look underneath tomorrow if anyone has had this problem before or ideas it would be much appreciated.