Meglio se cambi il tappo, lo faceva anche la mia.
C'è una valvola termostatica nel tappo, se si blocca può darti problemi al circuito di raffreddamento.
Cito da fonte esterna:
Your cooling system is a closed system, designed to build up pressure as the temperature rises. The higher pressure raises the boiling point of the coolant mixture. (Remember college physics?) When the temperature/pressure rises to the proper level, the valve in the radiator cap (yep, they have a valve - ever wonder what that spring is for?) causes the cap to open and the coolant to flow out to the overflow reservoir. As the coolant flows out, the pressure drops and the valve in the cap closes. As the engine cools, the valve opens in the other direction and the pressure drop in the radiator sucks the coolant back into the system, re-establishing equilibrium. Similar in operation to a thermostat, the cap can freeze up causing pressure problems in your cooling system, leading to an increased possibility of overheating. One symptom of a bad cap would be hearing a sound like a coffee percolator when you shut down. They are cheap enough that you should just plan on replacing yours every year or so.
C'è una valvola termostatica nel tappo, se si blocca può darti problemi al circuito di raffreddamento.
Cito da fonte esterna:
Your cooling system is a closed system, designed to build up pressure as the temperature rises. The higher pressure raises the boiling point of the coolant mixture. (Remember college physics?) When the temperature/pressure rises to the proper level, the valve in the radiator cap (yep, they have a valve - ever wonder what that spring is for?) causes the cap to open and the coolant to flow out to the overflow reservoir. As the coolant flows out, the pressure drops and the valve in the cap closes. As the engine cools, the valve opens in the other direction and the pressure drop in the radiator sucks the coolant back into the system, re-establishing equilibrium. Similar in operation to a thermostat, the cap can freeze up causing pressure problems in your cooling system, leading to an increased possibility of overheating. One symptom of a bad cap would be hearing a sound like a coffee percolator when you shut down. They are cheap enough that you should just plan on replacing yours every year or so.