The water flange is used as thermostat housing and as a connector between different pipes of the cooling circuit. Its function is to assure the flow of the cooling liquid and to maintain optimum coolant temperature to ensure proper functioning of the engine.
The use of poor quality coolant may result in the corrosion of this critical component. Exposure to high temperatures regularally may result in cracking. Constant vibration can loosen fasteners causing flange displacement internally. Standard wear and tear will also deteriorate this component.