Ford F-150 high pitch squealing noise persists for hours after engine shutdown, suspected modem issue on Ford F-150

Some Ford F-150 owners report experiencing a persistent high-pitched squealing noise that continues for hours after engine shutdown, which may indicate underlying mechanical issues. This noise, reminiscent of an old computer modem, could be linked to components such as the serpentine belt, alternator pulley, or idler pulley. If the noise persists even after the engine warms up, it may signal a more serious problem requiring immediate attention. Additionally, some owners find that the noise is associated with the power steering pump or a leak, necessitating repair by a mechanic. In certain cases, the noise may also be related to worn brake pads, especially if it occurs during braking. Adjusting the RPMs at idle can alter the noise, suggesting that using a tuner to raise the idle RPM might be a potential solution. It is strongly recommended that owners have their vehicles inspected by a qualified mechanic to diagnose the cause of this concerning noise, as ignoring it could lead to further damage and safety risks.