My engine starts to whine and whistle from the TBI area after I start my car in the morning and it warms up. I fixed 2 vacuum leaks that I had and tested all of the front engine pulleys, but it’s still wining and whistling. Do you know how I can stop this and what’s causing it?
Hello. I believe that you are experiencing a problem with the idle air control valve. It probably has built up some carbon. When the engine warms up it requires less air at idle so this valve closes a little more than when it is cold. When it closes enough, the carbon build up could cause a whistle sound to be made. It is possible that removing the valve and cleaning the carbon from the valve and out of the manifold/throttle body may cure the whistle. If cleaning does not work, it may be neccesary to replace the valve.