Cracked my thermostat housing

I would say second to none. Were you using a gasket or RTV as a sealant? Should use both with a thin film of RTV on both sides of the gasket. Torque spec is 12-17 lb-ft. Some may not know this about the T-stat installation.

To prevent incorrect installation of the water thermostat, the water hose connection on all engines contains a locking recess into which the water thermostat is turned and locked. Install the water thermostat with the bridge section in the water hose connection. Turn the water thermostat clockwise to lock it in position on the flats cast into the water hose connection. Install the water thermostat in water hose connection and lock water thermostat in place on flats cast into water hose connection.

Position the water thermostat, water hose connection gasket and water hose connection to the intake manifold. Install two retaining bolts and tighten to 16-24 N-m (12-17 lb-ft).


Most will just drop the T-stat into the intake and bolt down the housing. If the T-stat isn't properly seated you may end up cracking the housing as you did.