Subaru News (BLOG)

Welcome to Subaru News, Suburb Service’s monthly blog! Subaru News is meant to educate, entertain, and engage you in monthly musings on such topics as auto mechanics, Subarus, travel, auto repair, and driving and living in the Lake Forest Park and Shoreline area. Our blogs are released on the first day of each month!

Common Reasons Your Car Overheats

It's summer, and it's hot outside! Not that we are complaining, everyone needs a break from winter in the Pacific Northwest. But, no matter how much you love the heat, we can all agree that it can turn sour when it heats up inside where you would normally have a choice to be cooled off.

Especially if the victim of overheating is your Subaru. The summer weather doesn't necessarily determine a vehicle will overheat, but it also doesn't help the already hot situation. So, what does cause your car to overheat? There are so many possibilities, but they all have these two things in common: your engine is overheating, and something is causing a disruption in the cooling process.

Here are some of the most common reasons your car overheats

Leak in the Cooling System

Although a leak sounds bad, it's not actually what causes the actual damage directly. However, when there is a leak, it normally allows air to enter into the cooling system which causes air to be circulated and drops the coolant level. The air rises to the top, creating an airlock (i.e. a large bubble) that remains stuck since it cannot be pushed through with the normal flow.

This stops the cooling process, causing the engine to overheat. You could have a leak in you radiator, water pump, hose, head gasket, or thermostat housing. It may be hard to find the leak on your own, so make it easier on yourself and bring your Subaru into a mechanic to run the proper diagnostics.


Air pockets from a leak isn't the only thing that can create blockage within the system. Your thermostat may not be opening as wide as it should, there could be a mineral deposit blocking the radiator or a foreign object inside the cooling system. Sometimes dirt and road grime can enter in through your coolant hose and effectively block the flow of fluid from cooling your engine.

It's even possible that the wrong kind of coolant for the weather (especially in cold seasons) is causing the issue. If the coolant isn't concentrated enough, it can gel up inside the engine or radiator. The gelled coolant can not circulate and could cause potential internal damage. Be sure to flush your system and refill your coolant tank with the proper coolant for the season to prevent any issues.

Failed Water Pump

Because the water pump has such an important job - it pumps the engine coolant throughout the whole system - anything that goes wrong with the pump will affect the temperature of the engine. Parts of the pump, such as the bearing or impeller, can break overtime essentially stopping the flow of coolant. When this happens, it won't take long for the engine to overheat. You'll want to keep your eye out for any shifting of the pump shaft or eroded impeller vanes.

The main tip to keep in mind, is if you ever notice your engine overheating, either turn off your vehicle or turn on your heat to help let hot air out of the engine compartment while you drive straight to a mechanic. You do not want to put off an overheating engine, as it can result in engine failure and quite an expensive repair when ignored.

If you experience any engine disruption, or simply want to make sure everything is in top shape, click here to schedule an appointment at Suburb Service, or call (206) 705-8695 to reach our Seattle location. Show your Subaru some love.