- Risk of engine damage: Adding antifreeze to a hot engine can cause thermal shock, which can lead to cracking or warping of engine components. The sudden temperature change can cause the metal parts in the engine to expand or contract rapidly, putting stress on the engine and potentially causing damage.
- Increased pressure in the cooling system: Adding antifreeze to a running vehicle can also cause an increase in pressure within the cooling system. The antifreeze can expand when heated, and the closed cooling system may not be able to accommodate the additional volume, leading to a buildup of pressure. This can put stress on hoses, gaskets, and other components of the cooling system, potentially causing leaks or failures.
- Mixing of coolant types: If you are topping off the antifreeze level in a vehicle that already has coolant in the system, it is important to make sure that you are adding the same type of coolant as what is already there. Mixing different types of coolant can cause chemical reactions that can lead to the formation of sludge and other deposits, which can clog the cooling system and reduce its efficiency.
Therefore, it is generally recommended to add antifreeze to a vehicle when the engine is cool and the vehicle is not running. This will help to minimize the risk of engine damage, excessive pressure in the cooling system, and issues related to mixing coolant types.
