The heater core of your car is one of its most integral yet underappreciated components, using hot circulating engine coolant to heat and defrost windshields as well as supply air for cooling purposes and the AC system.
The heater core can affect air conditioning because if it malfunctions, it can allow hot coolant to circulate continuously, causing warm air to mix with the cooled air from the AC system, resulting in less effective cooling or warmer air output.
Heater core issues can be difficult to diagnose and repair on newer vehicles, particularly cars with easy engine bay access panels. Older models and some trucks, on the other hand, often require extensive interior disassembly work in order to gain access to their heater core and other components. Therefore, in most instances it would be wise to leave these tasks up to professional technicians.
When your heater core fails, its first sign may be an absence of warm air from the vents. Checking your cabin air filter may reveal dirt or debris clogging it. However, it could also be that the core itself has failed – although this would likely require special tools such as an inspection mirror or borescope to determine its failure.
Signs that something needs to be fixed quickly include an unpleasant sweet scent inside the car, often associated with the presence of ethylene glycol – used as coolant and toxic to humans if inhaled. Leakage could have occurred from your heater core; you must have this taken care of immediately!
Sometimes a heater core leak occurs simply due to age and wear; in other instances it could be the result of poor cooling system maintenance or the wrong type of coolant being used – for best results use only high-quality engine coolants designed specifically for your vehicle model year and model number.
One additional problem associated with electrolysis is the potential failure of the heater core. This chemical reaction causes tubing to corrode, leading to holes being created in the heater core and coolant leaking directly into the cabin and carpeting, or possibly spraying onto your engine, leading to overheating and costly engine damage.
An indication of a failing heater core is an increase in engine coolant consumption, since your engine must work harder to remain cool in response to its leak. If your coolant levels appear to be decreasing significantly, this may be an indicator that it needs to be replaced soon.