Your engine is driven by explosions of a fuel/air mixture inside the combustion chamber. When the fuel burns, a huge amount of heat is released, heating up the engine. If this is not controlled, the engine will quickly get overheated and fail. To prevent that from happening is the job of your cooling system, and the water pump as its key component.
The water pump does exactly what its name suggests, forcing coolant through the engine and your cooling system, so it can cool down and return to the motor. When flowing through the engine, the coolant absorbs excessive heat and transports it to the radiator, where it is released before the coolant gets back to the engine.
Attached to the front of the engine and properly sealed with a gasket, the pump is submerged into the coolant on the side where it features an impeller, also known as a centrifugal fan. On the other side of the pump, there is a pulley that is driven by a serpentine or drive belt connected to the crankshaft. The pulley and the impeller are coupled via a shaft, supported by a bearing assembly. The shaft spins the centrifugal fan when the engine is running, causing the impeller to pump the coolant.
The failure of the water pump means no coolant circulation through the engine and the cooling system. As a result, the excessive heat is collected inside the engine, causing engine overheating, which can turn into its severe damage. Fortunately, there are several common signs of a failing water pump, which can help you to detect and fix the problem before it causes catastrophic engine damage.
A faulty water pump is synonymous with engine overheating. Since the water pump doesn’t move coolant from the engine to the radiator, all excessive heat is collected in the combustion chamber, causing engine overheating.
Coolant leaks coming from the water pump area
A poor water pump gasket or its shaft can be a source of coolant leaks. If you notice the coolant level is getting low, or detect coolant leaks on the ground underneath the engine, you should inspect your water pump.
Your heater malfunctions
The heater relies on hot coolant to warm up air inside the cabin of your vehicle. If there is a lack of coolant due to a leaking water pump, the heater can malfunction.
The bearing assembly that supports your water pump’s shaft can wear out or get damaged, causing growling or rumbling noises.
What can cause my water pump to fail?
The most common water pump failures are a worn-out bearing assembly, a poor seal or gasket and a broken impeller. Most of them are caused by the following:
Rust and corrosion
A poor gasket or seal can allow different contaminants to access the impeller blades or shaft and damage them.
Like any part in a vehicle, your water pump can’t last forever. It can wear out over time.
A water pump is lubricated by coolant. If it runs dry due to a low coolant level, it may get damaged.
How to fix a bad water pump
If you detect any water pump leaks, you should not drive the vehicle due to the risk of engine overheating. Coolant leaks can lead to creating air pockets inside the cooling system, which can damage its components.
Your water pump should be checked by a professional before installing a new pump. In many cases, the signs of a failed water pump can be caused by a poor mounting gasket or seal. If the pump is the source of the problem, it must be replaced along with all gaskets and seals. It is also a good idea to replace your thermostat and flush the cooling system as well as to check your drive belt for signs of wear and replace it if necessary.