Does a failed water pump always leak?
Sometimes a water pump will fail internally. The pump may not be leaking, but the engine is overheating. If a cooling system pressure test shows the system is holding pressure (no internal leaks), and the problem is not a bad thermostat, a slipping fan clutch, or dead electric cooling fan, the water pump may not be pumping enough coolant. Some late-model water pumps have plastic impellers that are designed to reduce drag and noise. But over time, the fins on the plastic impeller can wear down, reducing the pump’s ability to circulate coolant through the engine. If the coolant contains any rust or sediment, it will accelerate the wear process. The same thing can happen to the blades on a metal impeller. Question: What are the different types of water pumps out there? Answer: Most water pumps are belt driven, but on some engines, the pump is driven by the timing belt. On most engines, the pump pulls coolant in through the lower radiator hose and routes it into the block and heads. On “re
