How to Tell if your Car Heater is Failing

Car heaters are one of the most important functions of a vehicle – and here’s why: Sometimes our most underappreciated vehicle functions fail in our vehicles, like car heaters. Those chilly mornings sneak up on us quickly, especially in the Tacoma area where Courtesy Auto Service and Tire is located. One day we are basking in the warm summer sun and the very next, it’s a windstorm mixed with a frost and sideways rain all at once. Our car heaters are our only hope against the creeping cold and we don’t know if our heater has gone out until it’s too late.

Luckily, Courtesy Auto Service and Tire of Tacoma, WA can service your car heater system to get it back in tip top shape. Don’t let the mornings mean you bundled up in a blanket on your way to work! Get that system back in working order. Get yourself a small thermometer to see just how cold it is in your vehicle and read on to learn more about what is going in with your heater.

Signs of a Failing Car Heater

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Thermostat Valve

A failing car heater can be a symptom of a more serious problem. A faulty thermostat valve may be to blame for the heater’s problems. This valve is responsible for the heater’s ability to heat the cabin. If you suspect the thermostat is to blame, you can perform some basic maintenance on your heater at Courtesy Auto Service and Tire.

Heater Core

First, you should clean the heater core. It is important to remove the seats and trim around the heater core and thoroughly clean it. You should use a dry cloth to clean it. If you can’t get this part clean, you may need to purchase a better vacuum cleaner. Hot air comes out of the heater core when the coolant flows through it, so it’s important to clean the core every once in a while, to prevent the heater from overheating.

If you aren’t comfortable cleaning this component yourself, just give us a call to get it taken care of for you.

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Coolant System

Failing car heaters can also indicate that the coolant in the system has become contaminated or the mix is incorrect. In some cases, a leak in the system is the culprit, but it’s best to consult a mechanic. An experienced mechanic will be able to diagnose and fix the issue. Using a professional is the best way to ensure your heater’s proper operation.


Another common sign of a failing car heater is fogging. This is caused by the warm coolant from the heater core evaporating into steam when it hits the colder air in the car. Similarly, a leaky car heater may emit a fruity or sickly-sweet smell from the engine.

Malfunctioning Engine

A failing car heater may also be a sign of a malfunctioning engine. A malfunctioned cooling system can lead to a number of other problems, including engine overheating. In particular, if your car is running very cold, your heater may be starved of coolant, which can lead to engine problems.

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A failing car heater can also cause overheating, which can affect many parts of your car. This may be the result of a leak in the coolant or the core itself. Likewise, it may also be the result of a malfunctioning blower motor. The latter may not be as complicated as the former, but you should always check for it in case it’s the heater core that’s the problem.

A failing car heater can make your daily commute a miserable experience. Not only will you be unable to defrost your windows and mirrors, but a failing car heater is also a safety hazard. The last thing you need to deal with is stranded in a cold car when the weather is bad.

To revive the heater in your vehicle, give us a call at 253-473-5556 or visit our contact page.