Coolant loss: The reservoir cap serves as a seal to keep the coolant inside the reservoir and prevent it from leaking out. If the reservoir cap is faulty or pops off, coolant can leak out of the reservoir, reducing the amount of coolant available to circulate through the engine and cool it. As a result, the engine may overheat.
Air in the cooling system: When the reservoir cap is not properly sealed, air can enter the cooling system. Air in the cooling system can create air pockets that prevent the coolant from circulating effectively. These air pockets can lead to hot spots in the engine and cause it to overheat.
Increased pressure: A faulty or missing reservoir cap can cause the pressure in the cooling system to increase. Excessive pressure can strain the components of the cooling system and lead to leaks or even a blown head gasket. This can result in the loss of coolant and further overheating of the engine.
Reduced boiling point: The reservoir cap helps maintain the correct pressure in the cooling system, which raises the boiling point of the coolant. If the reservoir cap is not functioning properly, the boiling point of the coolant can be reduced. This means that the coolant is more likely to boil and turn into steam, creating steam pockets in the cooling system that can lead to overheating.
Therefore, a faulty reservoir cap or one that pops off during driving can disrupt the normal functioning of the cooling system and contribute to overheating of the engine.
