2.4 LITER. Water pump stud. A threaded rod which is coupled with a nut in order to attach the thermostat housing to its mounting surface. A threaded rod which is used along with a nut to provide clamping force to help secure the Coolant Pipe to its mounting point. Engine Coolant Bypass Pipe Stud. Engine Water Pump Stud. Bypass. HexALOBULAR. Thermostat Housing. By - Passenger. Inlet. Thermostat hsng. Water Pump.