I recently have a check engine light and have shop fix it. they said it was the thermostat and CEL went out. Now the question is before my car temp will only go to about 185F max. after thermo replacement it always stay at 210F. in the morning it will take about 5 minutes to reach that temperature. Is this normal or they put a faulty thermostat?
Need all the info i can get. Thanks in advance to all...
It sounds like they may have installed and hotter rated thermostat. The OEM thermostat should be 186F for the 4.2 liter vortec. Bring it back to the place where you have the thermostat replaced and ask to have it checked with a scanner, the temperature sensor it self may have gone bad.
Good luck and keep us posted.
Engine Coolant Temperature (ECT) Sensor Replacement
Removal Procedure
Notice
Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.
Turn the engine OFF.
Caution
Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.
Disconnect the negative battery terminal.
Drain coolant below the level of the ECT sensor. Refer to Draining and Filling Cooling System in Engine Cooling.
Disconnect the ECT sensor electrical connector (1).
Remove the drive belt and the generator. Refer to Generator Replacement in Engine Electrical.
Carefully remove the ECT sensor (1).
Installation Procedure
Notice
Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.
Notice
Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.
If installing the original sensor or a new sensor without sealant, apply thread sealer P/N 12346004 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.
Install the ECT sensor. Tighten
Tighten the ECT sensor to 16 N·m (12 lb ft).
Connect the ECT electrical connector (1).
Install the generator and the drive belt. Refer to Generator Replacement in Engine Electrical.
Connect the negative battery terminal.
Refill the engine coolant. Refer to Draining and Filling Cooling System in Engine Cooling.
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Document ID# 735499
2002 GMC Truck Envoy - 4WD
