Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Coolant Temperature Sensor
The coolant temperature sensor is a variable resistor. It is located on engine block just below the No. 1 spark plug. It provides the fuel/timing control unit with information on engine temperature. When engine is below 27°F (-3°C), the sensor causes ignition timing to be advanced.
This is to ensure complete combustion of air/fuel mixture, providing good cold engine performance. Sensor also influences duty cycle during engine cranking. When temperature is less than 140°F (60°C) duty cycle (dwell) will be about 80%. At temperatures above 140°F (60°C), duty cycle will be about 50%.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.