There are very few engines left that still need air cooling. Either they are so small or well engineered or very badly engineered. Oil cooling or liquid cooling has taken the charge and air cooled engines have just become a thing of past for many manufacturers. So, with more efficient, cool & reliable engines, most people get out of tone of maintaining a coolant. Well, some might think it doesn’t need to be replaced, no it’s not!
Engine coolant is just like any other fluid running around the engine. Coolant’s filled up inside by manufacturers generally doesn’t need to be replaced frequently, but, they surely do need replacement. Every manufacturer set up an engine running time limit or total number of kilometers of the engine being driven, to get your coolant replaced. The replacement period is written in the user manual of your vehicle. Some vehicles such as Toyota Innova needs replacement of coolant over 1,30,000 kms while some cars such as Maruti Suzuki Swift need replacements above 70,000 kms. So, the replacement surely does matter upon the manufacturer and product.
If not replaced periodically, engine starts to overheat and if you are facing such a problem that means it’s time to change the coolant. Also minute particles from engine over a period of time get settled into the coolant that might lead to malfunctioning of the coolant. Get your coolant checked on each timed service of your vehicle, by a professional.
Some manufacturers recommend usage of anti freeze (though not used much now) but if you are doing by yourself, please do get proper information about the coolant you are using and the requirements of your vehicle. Such small maintenance bits increase the life of your vehicle and decrease hassle in your already hassle full life.[Image source : en.Wikipedia.com]