- Faulty Thermostat: A malfunctioning thermostat can prevent the coolant from circulating properly, causing the engine to overheat and leading to pressure buildup within the cooling system.
- Clogged Radiator: If the radiator is obstructed with debris or sediment, the coolant cannot dissipate heat effectively, resulting in overheating and subsequent antifreeze overflow in the overflow tank.
- Coolant Leak: A leak in the cooling system, such as a damaged radiator hose or a faulty gasket, can cause the coolant level to drop below the recommended level, leading to the overflow tank surging with air and coolant as the system attempts to replenish itself.
2. Faulty Pressure Cap:
- Lack of Sealing: A faulty or damaged pressure cap will not seal properly, allowing coolant to escape from the overflow tank as pressure builds up in the cooling system.
- Incorrect Pressure: If the pressure cap is not designed for the specific pressure requirements of the cooling system, it may not release pressure effectively, causing the overflow tank to surge.
3. Head Gasket Failure:
- A blown head gasket can allow exhaust gases to leak into the cooling system, resulting in excessive pressure buildup and a subsequent surge in the overflow tank.
4. Overfilling of Coolant:
- If the coolant reservoir is overfilled beyond the recommended level, it may overflow as pressure builds up within the system.
To accurately diagnose and resolve the issue, it is recommended to have a qualified mechanic inspect the cooling system, perform necessary tests (e.g., pressure testing), and make appropriate repairs.
