Coolant protects your PT Cruiser's engine from overheating, which can cause serious damage to your radiator, catalytic converter and other engine parts if it happens on a consistent basis. Your Cruiser's coolant system circulates coolant throughout the engine to cool it down. Coolant also has an antifreeze component and protects your engine from freezing in extremely cold weather.
Your PT Cruiser's engine has been designed to use Hybrid Organic Additive Technology, or HOAT, coolant. Chrysler recommends using Mopar Antifreeze/Coolant 5-Year/100,000 Mile Formula HOAT every time you replace your coolant. Introducing new types of coolant may compromise your engine's ability to process the liquid, which may shorten your engine's lifespan. If you use a different type of coolant in an emergency situation, such as if your car is overheating and is out of coolant, Chrysler recommends that you have your mechanic change it to HOAT coolant as soon as possible.
Hot, summer weather means that your engine is operating in higher-than-normal temperatures. Check your coolant reservoir, which is a plastic container inside your engine, to be sure that your coolant level is at a safe level. The marks on the coolant reservoir indicate the range in which your coolant level should be. Refill your coolant as necessary using a 50-50 pre-diluted mixture of HOAT coolant and water. Many coolant manufacturing companies, such as Mopar and Prestone, make pre-diluted coolant. You can find it at auto supply stores, supermarkets and mass-market retail stores.
Chrysler recommends that you check your PT Cruiser's coolant at least once every 12 months. The PT Cruiser engine is designed to use the same coolant for five years or 161,000 km (100,000 miles), but if it looks dirty or rusty, replace it by draining and refilling your coolant reservoir. Read your owner's manual for specific instructions on how to drain your coolant for your PT Cruiser's year and trim. To add new coolant, pour a 50-50 pre-diluted HOAT coolant-and-water mixture into your coolant reservoir until it reaches the mark on the outside of the reservoir. Use a funnel to avoid spilling coolant into your engine. You do not need to top it off with water if you use a pre-diluted coolant.