radiator fan running so fast

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. If the engine is cold and the air conditioning system is shut off, then I do not know why the fan would turn on. The fan would turn on if the climate control system is on, however, so that could possibly explain why it's on when you start your car. Testing can validate the demand for the fan actively running based on the input information provided to the processor. A shop near you equipped with proper diagnostic equipment would help diagnose the cause of what's going on. https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.