How to Know Your Heater Core Is Going Bad

Winter is the worst time for your car’s heater to be acting up. The heater core is responsible for warming up the air when you increase the temperature. It also warms the air for the defroster so you can see out the windshield despite the frigid air. Let’s look at the leading signs that your car’s heater core is going bad.

Fog on the interior

Maybe you’ve noticed fog is collecting on the inside of the windshield and windows in your car. There are two possible reasons for this. One is that the heater core is malfunctioning and, therefore, the defrosters aren’t working properly. The other possibility is that fog or smoke is being blown into the car’s cabin, which is also a bad sign. Either way, it’s best to have a professional mechanic check it out.

Strange smells

If you smell something sweet that’s reminiscent of fruit, this is one of the signs your car needs a new heater. The odd smell is the sign of a radiator fluid leak. This means that coolant is leaking into your car. Check the ground after you’ve parked the car to see how much has spilled out. Here again, you’ll want to have this problem addressed quickly by an automotive technician.

Chilly passenger compartment

This isn’t always a sign of a faulty heater core. It’s possible that your car has a blower motor or another part that has gone bad. That said, a lack of heat in the cabin is often due to the heater core malfunctioning. What often happens is that a hole develops in the heater core and all the warm air escapes quickly before it ever reaches the heater’s ducts. This means that cooler air is circulating inside—the exact opposite of what you want.

Air isn’t flowing through the vents

You turn on the heater, but there isn’t any air coming through. There are two possibilities here. One is that the blower motor is faulty, which means the fan speed doesn’t change. If you can feel a bit of residual warmth from the vents, then this is likely the case. But if you don’t feel even the slightest bit of warmth coming through, then it’s probably an issue with the heater core.

Frequent coolant loss

If your car is devouring coolant, this is a bad sign. It typically means there’s a coolant leak in the heater core. When you top off the coolant only to find that it’s low again the next day, bring it in right away for inspection.

Cold cabin/hot engine

Perhaps the interior of your car is cold—despite having the heater on—but the engine is still hot. Again, this is likely an issue with the coolant that can be linked to the heater core. The coolant is leaking before it ever gets to the engine.

Are you having car heater problems? Trust the certified auto technicians at Pat Doll Automotive to get to the bottom of the issue. We’ve been offering quality services since 1937—contact our shop today to set up your first appointment!