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Simple Answers from Protech Auto Service

Protech Auto Service

Heater cores are part of the engine cooling system that provides heat to the passenger compartment. Though it’s relatively easy to spot the signs of a bad heater core, the fix is a bit of a headache. Unfortunately, it’s also something that will get worse with time, so it’s worth taking care of as soon as failure is evident. Here’s what you need to know.


Heater cores are essentially mini-radiators. They use the same heat dissipation technology, with coolant flowing through the core to the rest of the system, and getting cooled as it does. The heater core, located just behind the firewall, also serves to bring in heat when you need it. When you turn on your interior heat, a fan behind the core starts up and blows this dissipated heat into the passenger compartment.

Bringing the heat

The most common problem heater cores develop are leaks. These can be pin-sized and hardly noticeable, or larger in the case of a connecting hose blowing off and spewing coolant everywhere. With smaller leaks, you might see only a tiny trace of coolant on the undercarriage, but if you notice a sizable puddle on the ground or your vehicle develops a voracious appetite for coolant, then your engine is at risk of overheating and you should get the issue repaired ASAP.

Smaller leaks might cause a light mist of warm coolant to blow into the passenger compartment, which will result in incurably foggy windows and a sweet smell. Coolant may also drip inside on the passenger floor once the engine has cooled. The heat supply itself may suffer, but keep in mind this could also be another problem such as a faulty fan or actuator.

Strengthening your core

Replacing the heater core is, admittedly, a pain. Because it’s buried behind several components on the other side of the firewall, the entire dash and anything standing in its way may have to be removed, including (depending on the design) panels, speakers and perhaps the steering wheel itself. Newer models packed with sensitive electronics make things even more challenging. This is another reason to consider letting the experts at Protech Auto Service handle this repair for you.

Once the technician removes enough components so he can see the actual heater core, changing the core is pretty simple. He just needs to disconnect the inlet and outlet lines, install the new heater core and then replace the dash and the other components in reverse order. The technician will then refill the vehicle’s coolant reservoir. Another reason to allow a professional to do the repair is that a DIYer can mistakenly disconnect the A/C system, which would vent toxic Freon into the atmosphere.

Even if the leak is small, it can take a toll over time — not to mention grow bigger. It’s also probably not great to be breathing in coolant on the regular. If you feel confident tackling the project yourself, pick up a new heater core and replace your faulty one right away. Otherwise, get it taken care of by a professional at Protech Auto Service to protect your engine’s cooling system from the disaster that is overheating. Another advantage with having a professional technician execute the repair is the shop warranty that comes with repairs being done at a reputable automotive repair shop.

For more information on the signs of a bad heater core, chat with one of the knowledgeable service advisers or technicians at Protech Auto Service. They can be reached at (661) 822-1100 and are located at 410 West J St., #G, Tehachapi.