When I first got my car, six weeks ago I had the high pitched whistle under very light throttle, after reading this forum I changed the air intake boot which was split on the smaller (idle control valve) side. I was amazed that this fixed it and very pleased.
This weekend I drove to Devon for a driving weekend on the moors and a bit of fun. Prior to this we changed a leaking water pump and thermostat housing, we also cleaned out the idle control valve with carb cleaner (my mates a Z3 expert).
Annoyingly the high pitch whistle has returned buy much quieter. We removed everything and double checked but all is good.
What else might cause this noise. Do ICV go faulty?
BTW, I still have water leak which must be the header tank or the pipe connection on it.
Thanks in advance.
This weekend I drove to Devon for a driving weekend on the moors and a bit of fun. Prior to this we changed a leaking water pump and thermostat housing, we also cleaned out the idle control valve with carb cleaner (my mates a Z3 expert).
Annoyingly the high pitch whistle has returned buy much quieter. We removed everything and double checked but all is good.
What else might cause this noise. Do ICV go faulty?
BTW, I still have water leak which must be the header tank or the pipe connection on it.
Thanks in advance.