idle air control valve

Hi, I am trying to solve an emissions problem with a freelander 1.8 petrol and noticed a high pitch ringing sound coming from the idle control valve when the ignition is turned on also after running the engine and then turning on ignition it makes clicking noises as well ,Can anyone confirm that this is normal as it sounds like its faulty to me.

They do whistle and sing, it is the stepper motor finding it's best position or searching if engine not running.
Contact PRO on this site. he has recently sorted the same thing and he changed the throttle position sensor, but it is not in a thread, we had a chat about it off line !!

Also, check the O2 sensor is working by downloading the app Torque and looking at the trace. It should be a sine wave from 0.2v to 0.8v or thereabouts. If it is stuck as a straight line change the sensor in the manifold.

Those are normal. In my case, emissions side, it was the upstream o2 sensor. Basically reporting porkies and sometimes there would be petrol on the cat with it's smell.
O2 needs looking after on voltage, etc. Cat could be on it's way out as well, there are many things but usually is the front o2 responsible for high emissions, unless bigger issues.

Hi guys, thanks for the info going to change the 02 sensor to see if that works

Good luck getting it unscrewed! Remove when exhaust warm. I cut the plug off mine, having found it faulty, and fitted a ring spanner to stop it rounding. You can buy O2 spanners with a slot for the wires.

Got it very easy, using a 24 open end wrench when engine is hot just one or two turns then continued in the morning
I found if you disconnect it, and then run the cable in the middle (upwards) between those 4 exhaust pipes it will spin freely.
Use gloves and e careful, not alot of room.