GM Service Manual Online
For 1990-2009 cars only

    Important: There were two types of thermostats used during the model year. An engine may have either dual thermostats or a single thermostat.


    Object Number: 64991  Size: SH
  1. Remove the bolts from the thermostat housing.

  2. Object Number: 59779  Size: SH
  3. Remove the thermostat housing.

  4. Object Number: 59780  Size: SH
  5. If the engine has a single thermostat, remove the gasket.

  6. Object Number: 59782  Size: SH
  7. If the engine has dual thermostats, remove the thermostats with the seals.