Description

Coolant Bypass Hose for the 4-cylinder petrol and naturally-aspirated diesel engines (non-TDi).

It forms the bypass path of the engine cooling circuit, allowing coolant to keep circulating through the block and cylinder head while the thermostat is still closed during warm-up. Once the engine reaches temperature and the thermostat opens, flow is shared with the radiator. A perished bypass hose is a common cause of coolant loss and slow warm-up.