Operation CHARM: Car repair manuals for everyone.

Thermostat Test

1. Use a temp stick in order to find the opening and the closing temperatures of the coolant thermostat.
- J 24731-188 temp stick melts at 87°C (188°F). The thermostat should begin to open.
- J 24731-206 temp stick melts at 97°C (206°F). The thermostat should be fully open.
2. Replace the coolant thermostat if it does not operate properly between this temperature range.