Hey y’all. I need some opinions. I have a 2006 fusion with the 2.3/4 Cylinder. At times while idling, the engine will have excessive vibrations. It also seems to stumble/buck while cruising between 50-60, which is also intermittent. I have replaced the spark plugs and valve cover gasket/ spark plug seals, also replaced the transmission mount/engine mount. The underside mount(torque mount) is not broken or worn at all, I even removed it and inspected it. The intermittent engine vibration is more harsh when the A/C cycles on, then gets less harsh when it cycles off. It is almost non existent when the A/C is not on at all. I have also noticed that when driving with the windows down and A/C off i can hear a whistling noise while accelerating(sounds similar to a turbo). I have sprayed carb cleaner/brake parts cleaner(method of checking for vacuum leak) all around the engine bay while idling and there was no increase in RPM’s. I did clean the throttle body, which had a “normal” amount of carbon build up, after cleaning the Throttle Body I did notice that it shifts smoother and the vibration seems to be less harsh, but still very noticeable.
So while cruising between 50-60 MPH, there is an intermittent bucking/ stumble, it does it most days, but then it won’t do it for a day or two. It does not have any Check engine lights or stored codes at all. Anyone experience this issue? Any help would be appreciated!
