BMW 135i Problem Report
BMW 135i Noise and/or Vibration Due to AC System Low on Refrigerant
A droning type noise may be noted when the air conditioning system is operating. Additionally, a vibration may be felt in the steering wheel. If these issues are no longer present when the AC system is turned off, the problem may be low refrigerant charge in the system. Our technicians remind us that if the refrigerant charge is found to be low, proper leak diagnoses should be performed in addition to recharging the AC system.