Your car's water pump is the core of the engine cooling structure. The water pump is the part that circulates the coolant from the engine to the radiator. Without this coolant circulation, the engine could overheat. It is important to understand the basics of how the water pump works and the signs of potential failure to protect your engine from overheating damage. Here's a look at what you should know about your car's water pump.

How Does it Work?

Most water pumps are belt-driven components. As a result, they're typically mounted to the front of the engine where you can run the belt across the pulleys. The water pump itself consists of an impeller crafted from either metal or plastic. The impeller has blades that force the coolant through the pump, and it is typically attached to a shaft on the pump housing. The shaft connects to the pump housing with a bearing and a seal to prevent leaks.

Problems with Water Pumps

There are two primary ways that water pumps fail. It's in your best interest to familiarize yourself with both so that you know what to watch for.

Leaky Seals

The seal between the water pump and the shaft is designed to keep coolant from seeping beyond the bearing. This kind of seeping can lead to significant coolant loss over time. Although these seals are durable, they are not infallible. They are vulnerable to wear from sediment, rust and other contaminants in the system.

Over time, the seal around the shaft will deteriorate and leak. Most vehicles require a specific level of coolant in the system for routine temperature maintenance. An undetected coolant leak can drop the level of coolant in the system below that level, causing the engine to overheat.

Impeller Failure

The other common problem with water pumps is complete failure of the impeller inside. If the impeller is made from plastic, it can erode due to the composition of the coolant. If the impeller stops running, it will no longer push coolant through the system. Without proper distribution of the coolant, your engine won't be able to cool down efficiently. This will lead to overheating. Impeller problems can be harder to detect because there is no visible coolant loss.

For impellers that deteriorate gradually, it may simply reduce the coolant flow until it's insufficient for the engine. You may still feel pressure in the system, but the amount of coolant flowing through won't be enough to keep things cool.

If your car is overheating or seems to be running warmer than it used to, it's important to evaluate the water pump condition before it fails. Otherwise, you may find yourself with an overheating engine and a damaged engine block. With the tips presented here, you can spot two of the most common water pump issues so that you can have it replaced (at mechanic shops like Cape Auto Repair) before it fails completely.