Gday all,
I have this persistant tapping/knocking coming from under the dash,its definatly mechanical in nature and it starts from the moment i start the car sitting in the drive way ,it taps/knocks a little bit more than every second,it doesnt seem to increase in tapping speed as i press the acelerator and once im moving general road/engine noise drowns it out so i dont know if it stops(i assume it doesnt).As i slow down for the lights etc i start to hear it ,it can vary in volume from a quiet tapping to reasonably loud and also it can stop for a second or two in idle but kicks right back in again.
Ive been to a mechanic and he said (shugs shoulders) maybe its a vacuum valve?under the dash and not from the engine bay(thankfully)
any sugestions would be greatly appreciated.
steve
98 st 4.5L Gu wagon