Chevrolet Citation/Omega/Phoenix/Skylark 1980-1985 Repair Guide



The factory-installed thermostat is designed to open at 195°F (91°C).


The thermostat is located inside a housing on the front of the cylinder head on the four cylinder engine, and inside the front of the intake manifold casting on the V6. It is not necessary to remove the radiator hose from the thermostat housing when removing the thermostat.

  1. Remove the two retaining bolts from the thermostat housing and lift up the housing with the hose attached.
  3. Remove the thermostat.

To install:

  1. Insert the new thermostat, spring end down.
  3. Apply a thin bead of silicone sealer to the housing mating surface and install the housing while the sealer is still wet. Tighten the housing retaining bolts to 6 ft. lbs. (8 Nm).

Poor heater output and slow warmup is often caused by a thermostat stuck in the open position; occasionally one sticks shut causing immediate overheating. Do not attempt to correct a chronic overheating condition by permanently removing the thermostat. Thermostat flow restriction is designed into the system; without it, localized overheating (due to coolant turbulence) may occur, causing expensive troubles.