What is the appropriate level for coolant?
2 Answers
The coolant should be filled to the middle position between the upper mark MAX and the lower mark MIN. Overfilling may cause overflow, and since coolant has certain corrosive properties, it can damage rubber components inside the vehicle. Underfilling may lead to freezing or even cracking of the engine or radiator in cold climates, and it won't provide sufficient cooling effect, potentially causing engine failure. Coolant is generally divided into three types: ethanol-water, glycerol-water, and ethylene glycol-water. Ethanol has a freezing point of -114 degrees and a boiling point of 78.3 degrees. It is flammable and prone to evaporation, so its content in the mixture should generally not exceed 40%, and it is not suitable for use in diesel engine cooling systems with higher operating temperatures.
I've been driving for over twenty years and found that the coolant level must be checked when the engine is cold by looking at the marks on the expansion tank. That transparent plastic tank has MIN and MAX lines, and the water level should be right in the middle. If it's too high, the liquid will expand when the engine heats up and overflow, dirtying the engine bay. If it's too low, the system will lack water, leading to poor cooling, and in winter, it might even freeze and block the pipes. I check it routinely every month, especially during seasonal transitions. In summer, the high temperatures cause the liquid to evaporate faster, so you need to pay extra attention and top it up with the same type of coolant. Never cut corners by using water as a substitute—it has poor anti-boil and anti-rust effects, and long-term use will cause the system to rust and age quickly. If the water level keeps dropping too fast, there might be a leak in the pipes or a crack in the radiator, so take it to a repair shop as soon as possible to get it checked.
