How to Replace a Thermostat on a Mazda Mx6

The thermostat on a Mazda MX6 is important for regulating the engine temperature. The thermostat ensures the car does not overheat by allowing coolant to flow through the engine when the engine reaches a set temperature. The thermostat opens to release the coolant into the engine block and then closes once the engine is below the regulated temperature. Replacement of the thermostat does not take very long as it is found adjacent to the air filter and distributor.

Things You'll Need

  • Socket wrench
  • Socket set
  • Flat tip screwdriver
  • Open the hood for access to the engine compartment. Open the top of the air intake box found on the top of the engine. Unscrew the bolt at the outside bottom of the air filter assembly with a socket wrench. Don't bother to take the air filter out -- remove the whole assembly. Unscrew the air intake line connected to the air filter assembly with a flat tip screwdriver. Loosen the hose clamp. Pull the air filter box out of the engine compartment.

  • Remove the two bolts on the distributor cap below the air filter housing with a socket wrench. Do not remove the spark plug wires from the distributor. Move the distributor cap to the side. This allows more room for working.

  • Note the location of the thermostat housing near the distributor. The radiator hose connects to it and attaches to the engine block by two bolts. Use a socket wrench to remove the two bolts and pull the thermostat housing away from the engine.

  • Remove the thermostat from the assembly. Note its positioning inside the thermostat housing before moving it.

  • Use a razor scraper to clear old gasket material from the engine block where it mates with the thermostat housing. Clean all gasket material from the thermostat housing as well. Wipe with a clean rag to ensure all gasket material is gone.

  • Insert the new thermostat with the spring toward the engine and the tiny round cylinder tab on top. Ensure it is in the same position as the old one. The thermostat spring opens the thermostat to allow coolant into the engine. If it is place backwards, coolant cannot flow into the engine causing it to overheat.

  • Bolt the thermostat housing with the gasket onto the engine block with a socket wrench. Ensure the bolts are tight.

  • Secure the distributor cap with a socket wrench. Return the air filter box and tighten the bolt at the bottom. Install the air duct hose and tighten the hose clamp with a flat tip screwdriver.

  • Twist off the radiator cap. Inspect the coolant level of the radiator. Add the appropriate coolant mixture to the radiator.

  • Start the Mazda Mx6 engine and allow it to idle for five minutes. Ensure the thermostat engages -- note this by coolant level drops. Add coolant as needed.

  • Tighten the radiator cap onto the radiator. Close the hood. After driving the engine, check the coolant level again to ensure the appropriate amount of fluid is available in the radiator. Fill the radiator or overflow container with coolant as appropriate.