If the fan assembly free-wheels without drag (the fan blades will revolve more than five turns when spun by hand), replace the fan drivThis spin test must be performed when the engine is cool.

• 如果风扇组合空转没有阻力（用手拨一下风扇，叶片能旋转5圈以上），更换风扇驱动。该旋转测试必须在引擎冷却的时候进行。