1. Overheating: Your car might be overheating due to a problem with the cooling system, which can cause coolant to overflow. Check your thermostat and water pump to ensure they're functioning properly.
2. Faulty Radiator Cap: A faulty radiator cap may not be releasing pressure correctly, leading to coolant overflow. Replace the radiator cap if it's old or damaged.
3. Leaking Head Gasket: A blown or leaking head gasket can also lead to coolant overflow and affect cabin heating. When this happens, exhaust gases can leak into the coolant system and interfere with the heater core's ability to produce warm air.
4. Blocked Radiator or Heater Core: Blockages in the radiator or heater core can prevent proper coolant circulation and reduce heating efficiency. Check for any obstructions or debris that may be hindering fluid flow.
5. Faulty Fan Switch or Relay: If your radiator fan isn't working correctly due to a faulty fan switch or relay, the engine may overheat, causing coolant to overflow. Check the wiring and electrical connections to ensure the fan can turn on when needed.
6. Low Coolant Level: If your coolant level is low, it may not be sufficient to cool the engine properly. Check the coolant reservoir and add more coolant if necessary, then check for leaks in the cooling system.
7. Air in the Cooling System: Air pockets trapped in the cooling system can cause overheating and prevent proper circulation. Try bleeding the cooling system to remove any trapped air.
8. Faulty Heater Control Valve: A malfunctioning heater control valve may not allow hot coolant to flow into the heater core, resulting in cold air from the vents. Check the operation and condition of this valve.
Since the issue involves engine cooling and cabin heating, it's best to have a qualified mechanic diagnose the exact problem and perform the necessary repairs.
