How to Change the Coolant Temperature Sensor in Vehicles

The Vehicles was equipped with several different engines, but all engines were equipped with an electronic temperature gauge. The gauge reads the signal produced by a coolant temperature sensor within the engine. When the sensor is defective, it simply stops working rather than slowly losing its accuracy. Fortunately, replacing the sensor in a Vehicles is a straightforward task.

Under The Hood:

• How to Change the Coolant Temperature Sensor in a 2000 Buick
• How to Change a Coolant Temperature Sensor on a Northstar
• How to Change the Coolant Temperature Sensor on a Mazda 626

 How to Change the Coolant Temperature Sensor in a 2000 Buick

Locate the sensor on the side of the radiator, just below the radiator cap.

Twist the radiator cap off of the radiator after allowing the radiator to cool. Never remove the cap when the engine is warm, as its contents are under pressure and can cause severe burns.

Position a sealable container underneath the drain bolt at the base of the radiator, then remove the drain plug with a wrench and allow the radiator to drain into the container until the coolant level falls below the level of the sensor. Replace the drain plug.

Unplug the electrical connector from the bottom of the sensor.

Lift one leg of the snap clip which secures the sensor against the radiator with needle-nose pliers, then pull the sensor out of the radiator.

Lubricate the O-ring supplied with the replacement sensor with clean radiator coolant, then position the O-ring onto the sensor.

Position the snap clip into place on the sensor, then press the sensor onto the radiator until the sensor clicks into place.

Fill the radiator with DEX-COOL coolant, then install the radiator cap.

 How to Change a Coolant Temperature Sensor on a Northstar

Drain the radiator coolant into a container by removing the bolt at the base of the radiator with a wrench.

Pull the electrical harness off of the sensor. The sensor is located on the passenger’s side of the front of the engine and faces the back of the radiator.

Remove the sensor with a deep-set socket wrench.

Coat the threads of the new sensor with General Motors gasket sealing compound, part number 1050805.

Tighten the new sensor to 15 ft.-lbs. of torque with a torque wrench.

Connect the electrical harness to the sensor.

Tighten the radiator’s drain bolt with a wrench then fill the radiator with the drained coolant.

 How to Change the Coolant Temperature Sensor on a Mazda 626

Remove the radiator cap from the passenger’s side of the top of the radiator after allowing the engine to cool.

Open the radiator draincock at the bottom of the radiator with a wrench and allow it to drain, then close the draincock.

Locate the temperature sensor on the top of the water outlet. The water outlet is located on the top of the engine, on the end of the cylinder head.

Pull the single wire located on the tip of the sensor off the sensor.

Rotate the sensor in a counterclockwise direction with a wrench until the sensor detaches from the water outlet.

Count the first three threads on the replacement sensor’s threaded rod starting from the bottom of the rod to find the gasket sealant’s application area. Gasket sealant must not be applied to the bottom three threads.

Apply gasket sealant to the application area of the replacement sensor.

Rotate the sensor in a clockwise direction with a wrench until the sensor is secured to the water outlet.

Plug the sensor’s single wire into the tip of the sensor.

Refill the radiator with a 50/50 mixture of water and ethylene glycol antifreeze that is labeled as safe to use with aluminum radiators, then tighten the radiator cap onto the radiator.