1. Open the hood of your vehicle.
2. Locate the thermostat housing. On the 2001 Mazda 626 LX V6, it is located on the front of the engine, near the top. It is a round, metal housing with a hose attached to it.
3. Remove the bolts that hold the thermostat housing in place. There are two bolts, one on each side of the housing.
4. Once the bolts are removed, you can carefully pry the thermostat housing off of the engine. Be careful not to spill any coolant that may be inside the housing.
5. The thermostat is located inside the thermostat housing. It is a small, round, metal disk with a spring-loaded valve in the center.
6. To remove the thermostat, simply pry it out of the housing with a flat-head screwdriver.
7. Inspect the thermostat for damage. If the thermostat is damaged, it will need to be replaced.
8. Install the new thermostat in the housing. Make sure that the thermostat is seated properly in the housing and that the spring-loaded valve is facing up.
9. Replace the thermostat housing and tighten the bolts.
10. Refill the coolant system.
