The Mazda 626 is a sedan that comes equipped with a 2.0-liter or 2.5-liter, four-cylinder engine. If all systems are operating properly, the engine temperature of your 626 will be properly regulated and you won't experience any issues with overheating. If you find that your 626 is consistently running hot or completely overheating, there are a number of areas you can check to see if you can pinpoint the problem yourself. It might be an easy fix or a more complicated one requiring the help of a trained mechanic.
Check to make sure you have enough coolant in your 626's coolant reservoir, which is located in the front near the passenger side headlight. The coolant in the reservoir should be between the F and L markings. Add coolant if necessary.
Wait until the engine is cold and check to see if the radiator is filled with coolant. Remove the radiator cap, which is located in the front left side of the vehicle. You should be able to see coolant near the top of the radiator. If you don't, add coolant directly to the radiator.
Check to see if there are any leaks in the hoses leading to and from the radiator, especially if you've noticed the coolant was low. The rubber hoses can dry out over time and develop cracks, which will allow coolant to leak out.
Check the hoses to be sure there isn't a kinked hose, which will restrict the flow of coolant within the system.
Replace the thermostat. It is not uncommon for the thermostat, which regulates the flow of coolant, to be stuck in the closed position. When this happens, it will cause the engine to overheat.
Pressure test the coolant system, which will help identify if there is a leak in the system. A pressure gauge is connected to the cooling system, and if the pressure falls once the vehicle hits normal operating temperature, that is a sign there is a leak that needs to be repaired.
