Will a Faulty Thermostat Affect the Electric Fan in a BMW 5 Series?

[DelJesse]

A faulty thermostat in a BMW 5 Series will affect the electric fan. The thermostat controls the operation of the cooling fan. If the thermostat is broken, it can no longer control the fan, causing the fan to either run continuously or not at all. How the Car Electric Fan Works: The car electric fan is controlled by a thermostat. When the coolant temperature rises to the upper limit, the thermostat activates the power supply, and the fan starts working. When the temperature drops to the lower limit, the thermostat cuts off the power, and the fan stops. Function of the Car Electric Fan: It cools the engine block and transmission and dissipates heat from the air conditioning condenser. Steps to Replace the Electric Fan: 1. Open the car's hood and remove the intake pipe located above the fan. 2. Use professional tools to unscrew the bolts. 3. After removing all the bolts, take the fan off the vehicle. 4. Install the new fan correctly on the new fan bracket and tighten the four fixing bolts. 5. Start the engine to test whether the fan operates normally. After confirming everything is correct, reinstall the intake pipe to its proper position.

[DaisyLee]

As a BMW owner, I've had to fix the cooling system issues on the 5 Series several times. The thermostat controls the engine temperature, and if it fails, it can get stuck in either the open or closed position. If it gets stuck closed, the coolant won't circulate, causing the engine temperature to skyrocket, and the electric fan will run at full speed continuously trying to cool it down—this drains more power and strains the battery. If it gets stuck open, the temperature may drop too low, and the fan might not activate, leading to insufficient cooling. BMW's ECU system is quite smart—it detects abnormal temperatures and responds with high-frequency fan operation. In a real-life case, a friend's car had the fan screaming for a week before the motor burned out. I recommend checking the dashboard for the coolant temperature warning light—don't wait until the engine overheats to fix it. When replacing the thermostat, it's cost-effective and reassuring to change the coolant at the same time.

[JohnnyRose]

My 5 Series had a similar issue after long-term use. That time, the thermostat failed causing the fan to roar constantly - it wouldn't stop even after turning off the car, draining the battery badly. The technician explained the temperature sensor malfunction made ECU misread signals, forcing the fan to work continuously to protect the engine. During highway driving, even the AC performance deteriorated with weaker cooling. After personally checking fuses and wiring connections (all normal), replacing the thermostat solved it. Key things for daily driving: monitor fan noise and coolant temperature gauge closely. BMW's electronic systems are sensitive - minor issues may escalate. Timely repairs prevent premature battery failure, saving both fuel and maintenance costs.

[LaLyla]

A faulty thermostat will definitely affect the fan operation. I've encountered abnormal fan operation in a BMW 5 Series due to temperature control failure. The ECU relies on thermostat signals to control fan speed – when faulty, the fan runs at high speed for prolonged periods, wearing out the motor. In preventive maintenance, regularly replacing coolant and checking thermostat sealing can reduce risks. These simple steps extend component lifespan, and safe driving remains the top priority.