How to Install a Thermostat on a BMW 323ic

1. Remove the radiator hose from the thermostat housing by loosening the retaining clip that secures the hose onto the housing with the screwdriver. Pull the hose off the thermostat housing and hold it vertical so the antifreeze goes back into the radiator. Push the hose off to the side to make accessing the thermostat housing easier.
2. Remove the 10 mm bolts that hold the thermostat housing onto the intake manifold of the BMW with the wrench and then pull the thermostat housing off the intake manifold.
3. Remove the old thermostat and then place the new one into the intake manifold. The thermostat sits on a machined lip that is located below the level of antifreeze. The thermostat should be properly seated to ensure it works correctly.
4. Pull the old thermostat gasket off the intake manifold and place a bead of RTV gasket sealer in its place on the intake manifold. Place the paper thermostat gasket on top of the RTV gasket sealer. Place a small amount of RTV gasket sealer on the bottom of the thermostat housing and then bolt the housing back into place.
5. Place the radiator hose back onto the thermostat housing and secure the retaining clip into place.
6. Start the engine and allow it to warm up. Inspect for leaks where the thermostat housing is bolted to the intake manifold and where the radiator hose connects to the housing. If the radiator hose leaks, replace the retaining clip with a band clamp. If the area where the housing and the manifold bolts together leaks, tighten the housing bolts more.