The throttle passage of the old Jetta is blocked.

The normal working water temperature of the public is about 90 degrees. If you feel the water temperature is high, check it carefully. 1, check whether the coolant is sufficient. 2. Check the whole engine and cooling system for coolant leakage and penetration. Comprises a water tank, a water pump, water inlet and outlet pipes and joints, a heating box, a wave box, a throttle body and other cooling water pipes. 3. Check whether the pipes of the cooling system are partially blocked, whether there is too much scale in the water tank, and whether the large and small water pipes are unblocked. 4. Check whether the circulation of the cooling system is good. Whether the pump impeller falls off or whether the pump is damaged. Whether the belt driving the water pump is loose or damaged. The thermostat can only be opened in water with a temperature of about 90 degrees. Check whether the thermostat used is like this. 5. Check whether the cooling system has good heat dissipation. Whether the cooling fan and its circuit are in good condition, and the circuit cannot be virtually connected. Whether the water temperature sensor or temperature control switch and its circuit and relay are in good condition. Whether the outside of the water tank is dirty and whether the shutters are ventilated. 6. Check whether the engine has cylinder flushing phenomenon and whether the cylinder gasket seal is bad. Whether there are cracks in the cylinder block and cylinder head. Whether the oil radiator is damaged. 7. Check whether the engine valve timing is correct.