Symptoms
- Fan noise from under the hood or trunk area during or after fast charging
- Noise also occurs after hard acceleration or highway driving
- Fan runs even when the car is off, for a period after parking
- Noise level seems louder than it used to be
Likely causes
- CommonNormal battery cooling during or after fast chargingFast charging generates heat, and the cooling system runs the fan to keep the battery in a safe temperature range, sometimes continuing briefly after you stop.
- CommonNormal cooling after hard driving or hot weatherAggressive driving or high ambient temperatures increase cooling demand on the battery and motor.
- PossibleDirty or obstructed radiator/cooling intakeDebris blocking airflow can make the system work harder and the fan run louder or longer than normal.
- PossibleFailing fan motor or bearingAn aging fan motor can become louder or rougher-sounding as it wears.
What to do
- Note if the loud fan coincides with fast charging, hot weather, or hard driving, which are all normal triggers for extra cooling.
- Check the front grille or cooling intakes for visible debris, leaves, or dirt blocking airflow, and clear it if accessible.
- Time how long the fan runs after parking; a period of continued running after a fast charge or hard drive is often normal.
- Compare the sound to when the car was newer, if possible, to judge whether it's genuinely louder or just more noticeable.
- If the fan runs constantly even when parked and cool, or makes a grinding or rattling sound, that's different from normal cooling noise.
- Avoid blocking any cooling vents or intakes with covers or accessories.
Tools and parts
Cooling fan assemblySearch: “battery or motor cooling fan for your EV make, model, and year”
When to call a pro
If the fan runs constantly at idle with the car cool, or makes a grinding noise, have a dealer inspect the cooling fan and system.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.