How To Determine A Faulty Auto A/C Evaporator

The auto A/C evaporator is one of the vehicle’s most important air conditioning components, but it is vulnerable to a number of issues, such as weak air flow, temperature fluctuations and unusual odors. Below are some reasons why these things occur, and how drivers should respond.

Why The Evaporator Is So Important

The last thing most drivers want to deal with on a hot, sweltering day is a malfunctioning A/C unit, but this is when it is most likely to happen. Contemporary air conditioning systems consist of various components which are independent and yet must function together in a seamless manner so that warm air can be converted to air which is cool. The evaporator plays a key role in this process, but is susceptible to problems that can appear without warning.

The goal of every A/C system is to extract heat from air. The evaporator is tasked with managing the refrigerant while it remains in a liquid state. Warm air will traverse the coils of the evaporator, where it collects surrounding air heat and cools it down. Afterwards the cool air is circulated throughout the vehicle’s cabin. The evaporator is made up of two components, which are the coils and core. When problems occur, it usually involves leaks which are present between the two subcomponents.  Since evaporators need continual pressure so that heat can be efficiently removed, this leakage if left unresolved will lead to malfunction.

The Compressor Won’t Activate

The purpose of the compressor is to circulate refrigerant within the evaporator. However, in order to do so it must maintain a pressure which is predetermined. If a leak is present, pressure will be reduced and as a consequence the compressor won’t activate.

The Airflow Is Weak Or Not Cool Enough

When either the core or coil is leaking, the A/C effectiveness will be severely compromised. In fact, the seriousness of the leak indicates the severity in cooling capacity.

You Detect A Strange Or Unpleasant Scent From The A/C

When the evaporator leaks, a small bit of refrigerant (not the coolant) will be emitted from the core, seals or coil. This will create a scent which is sweet, which will increase in intensity whenever the air conditioning is activated.

You Notice Fluctuating A/C Temperatures

Evaporators which have small leaks might continue cooling the air. However, should the temperature fluctuate, this means the evaporator might be damaged.

The Outer Seal Is Damaged Or Corroded

The majority of leaks result from damage to the evaporator core’s outer seal, so it is important to check for this (or mention it to a mechanic). Another issue to be mindful of is corrosion. This is a known problem within evaporator cores and is one of the things which cause the seals to leak. It results from debris that gets inside your air intake, which can lead to air filters which are either clogged or damaged.