My 2000 Mustang
3.8 V6 5 gear was idling at 1300-1500 rpm.
I cleaned the IAC valve but then it made a weird 'screeching' noise from somewhere
in the throttle body and cut out when I took my foot off the accelerator.
I put it in the garage and they replaced the IAC, but they could only find a used unit to replace it with (I live in Spain).
The car still idles at 1500 rpm until it has been driven for some time. This is a nuisance, especially when using the engine to reduce speed on downhill stretches. My manual says it is not possible to adjust the idle speed and that I should take it to a Ford dealer.
Any suggestions please?