LEMON Manuals: Even more car manuals for everyone
Home >> Pontiac >> 2005 >> Grand Prix GXP >> Repair and Diagnosis >> Engine Mechanical >> Cooling System (Mechanical) >> Engine Cooling System >> Diagnostic Information and Procedures >> Thermostat Diagnosis (Overheating)

Thermostat Diagnosis (Overheating)

Thermostat Diagnosis (Overheating)

Step Action Yes No
IMPORTANT: The J 24731  Tempil Stick is a pencil-like device that has a wax material containing certain chemicals which melt at a given temperature. See Special Tools . Use the temperature sticks to determine a thermostats operating temperature by rubbing 87°C (188°F) and 97°C (206°F) sticks on the coolant outlet. The marks made by the sticks should melt when coolant temperatures reach 87°C (188°F) and 97°C (206°F), respectively. These temperatures are the normal operating range of the thermostat.
1
  1. Remove the radiator cap. Refer to Draining and Filling Cooling System (L26 and L32)  or Draining and Filling Cooling System (LS4) .
  2. Rub a 97°C (206°F) J 24731  on the coolant outlet. See Special Tools .
  3. Warm up the engine at fast idle.
  4. Check for coolant flow before the mark begins to melt.
Is there coolant flow before the mark melts?		 Go to Step 2  Go to Step 3 
2 The problem is caused from something other than the thermostat. Refer to Engine Overheating .
Does the engine still overheat?		 - System OK
3
  1. Replace the thermostat. Refer to Thermostat Replacement (RPOs L26/L32)  or Thermostat Replacement (RPO LS4) .
  2. Check the system
Is the engine still overheating?		 - System OK
scientia non olet · About LEMON Manuals