For 1990-2009 cars

### Removal Procedure

1. Turn OFF the ignition.
2. Relieve the coolant pressure.
3. Disconnect the engine coolant temperature (ECT) sensor electrical connector.
4. Use a deep well socket and an extension in order to remove the sensor.

### Installation Procedure

1. Coat the ECT sensor threads with sealer GM P/N 9985253 or equivalent.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Install the sensor in the engine.

Tighten
Tighten the sensor to 23 N·m (17 lb ft).

3. Connect the ECT sensor electrical connector.
4. Start the engine.
5. Inspect for leaks.
6. Inspect the coolant level.