Genuine Mazda MX-5 Miata Thermostat

Mazda MX-5 Miata Thermostat Parts and Q&A

• Thermostat
  L336-15-170
  Q: What steps should be taken before assuming the thermostat is responsible for a cooling system problem on Mazda MX-5 Miata?

  A:

  The level of the coolant, tension of the drive belt, and working of the temperature gauge or light should be checked before concluding that a problem exists with the cooling system and the thermostat is the cause. In case the engine takes a long time to warm up, it is likely that the thermostat is stuck in the open position and needs to be replaced. When the engine becomes hot and the upper Radiator hose is not warm, the thermostat can be stuck and the coolant cannot flow through the radiator and it has to be replaced. Driving without a thermostat is not recommended because it may cause poor emissions and fuel economy. Should the hose be hot, the flow of coolant is on, and this indicates that the thermostat is open. Unmount the negative cable on the battery and empty the radiator of the coolant. In the 2005 and earlier models, unscrew the thermostat cover electrical connector, the thermoswitch, loosen radiator hose clamp and remove hose. Unscrew the thermostat cover, anticipate coolant spillage, and unscrew the thermostat, with a note of its direction of installation. Clean the sealing surfaces, place the new thermostat with spring end at the bottom or towards engine as per the year of production, install a new gasket and check the alignment correctly. Installation is the opposite of removing, which involves securing the thermostat cover fasteners to the required torque. Re-fill the cooling system, start the engine and look after any leaks and functionality. In 2006 and recent models, disassemble throttle body, disconnect bypass and radiator hose, and loosen bolts of thermostat housing. Dispose of the old gasket, when re-assembling, make sure that a new gasket is used and when fitting bolts tighten to the required torque. Re-fill the cooling system, start the engine and look after any leaks and functionality.