Engine Coolant Thermostat with Seal (762-189) by MotoRad®. Temperature: 189F. State-of-the-art equipment, strict quality control, and functional testing to each thermostat ensure customers that they can trust the high-quality product used in their vehicle. As cooling system experts, MotoRad knows what is necessary to manufacture a high-quality part that will stand up to the rigors of today’s demanding cooling system environments where others fail.