How are you determining it's over heating ? Going by the temp gauge in the instrument cluster ? Did you hook up a scan tool to view coolant temp sensor parameters ? What the PCM - engine computer is seeing . Use a infrared thermometer to see what the engine temp is for real .
Do the cooling fans work ? If fans work an temp is in spec's , by scan tool an infrared thermometer testing the instrument cluster is faulty . GM had problems with stepper motors inside the instrument cluster model years 2003 to 2006 . The stepper motor is what drives the gauges .
https://www.youtube.com/watch?v=oTm2oDx-_GM
The PCM commands Low Speed Fans on under the following conditions:
• Engine coolant temperature exceeds approximately 106°C (223°F).
• When A/C is requested and the ambient temperature is more than 50°C (122°F).
• A/C refrigerant pressure exceeds 1 310 kPa (190 psi).
• After the vehicle is shut off if the engine coolant temperature at key-off is more than 140°C (284°F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes.
The PCM commands High Speed Fans on under the following conditions:
• Engine coolant temperature reaches 110°C (230°F).
• A/C refrigerant pressure exceeds 1 655 kPa (240 psi).
• When certain DTCs set
When the request for fan activation is withdrawn, the fan may not turn OFF until the ignition switch is moved to the OFF position or the vehicle speed exceeds approximately 10 mph. This is to prevent a fan from cycling ON and OFF excessively at idle.
This is why you take your vehicle to a qualified repair shop . They have the knowledge an tools to diagnose correctly . Not just start replacing thing's not needed .
×