4 Signs of a Failing AC Evaporator

One of the most frustrating situations any car owner can experience is a broken AC, especially during those hot summer days. The modern AC system is comprised of multiple independent components that must work together seamlessly in order to convert warm air to cool. Of these parts, the AC evaporator is crucial to an automotive air conditioner. While this component can hold up against constant use for several years, problems can and often will pop up without warning.

What is the AC Evaporator?

An air conditioning system is designed to remove heat from the air. The job of the evaporator is to harness the cold refrigerant in its liquid state. As warm air passes along the evaporator coils, it collects the heat from the air and makes it cool. The cold air is then circulated through time cabin.

Two specific components that make up the evaporator: the core and the coils. When issues occur, in most cases it’s due to leaks created in between these two parts. Since the AC evaporator requires constant pressure to effectively remove heat, a leak is typically the leading cause of a malfunction. As such, when a major AC Evaporator leak is detected, replacement is the best course of action.

4 Symptoms of a Bad or Failing Air Conditioning Evaporator

Like most AC issues, the first indicator of a damaged AC evaporator is poor performance. Since the AC evaporator is the major part that removes heat from the air, failure is rather simple to determine. However, there are 4 other warning signs of a damaged AC evaporator:

  • 1. The cool air is weak or no cold air is blowing at all. When the AC Evaporator coil or core is leaking, it will impact the effectiveness of the air conditioning system. Generally speaking, the greater the leak, the cooling capacity is reduced.

  • 2. You notice a strange odor when using your AC system. If your AC evaporator is leaking, a small amount of refrigerant (not coolant) will seep from the coil, core, or seals. This will produce a sweet aroma, which might get more intense when the AC is turned on.

  • 3. The AC compressor will not activate. The compressor is intended to circulate refrigerant through the evaporator. It depends on maintaining a predetermined pressure to operate. As such, if there is a leak, there is reduced pressure within the system and the compressor will not activate.

  • 4. The AC temperature will vary. If the AC evaporator has a small leak, it can continue to cool air. However, if the temperature is inconsistent, it’s a possible indicator of a damaged AC evaporator.

What are the Main Causes of an AC Evaporator Leak?

There are a few sources of an AC evaporator leak. Some of them easy to detect, and others requiring some detailed diagnosis:

  • 1. Damaged Outer Seal.Most leaks are due to a damaged outer seal on the evaporator core.

  • 2. Corrosion. It’s also quite common for corrosion inside the evaporator core to cause seals to leak. Corrosion occurs when debris finds a way into the air intake such as dirt caused by damaged or clogged air filters.

  • 3. The Connection between Coil and Core.Another leak source is the connection between the ac evaporator coil and the core. If a leak is detected, replacement of the entire AC evaporator is the correct course of action.

Some shade-tree mechanics attempt using a sealant to fix a leak, but this is always a temporary solution, and typically creates additional problems with the AC system — so we don’t recommend this type of quick-fix.


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Jeremy

20 years of experience
428 reviews
Jeremy
20 years of experience
Toyota Tundra - AC is not working - West Palm Beach, Florida
Jeremy was awesome. What a great experience. I will definitely use this service again. Thank you so much
Dodge Grand Caravan - AC is not working - Boynton Beach, Florida
Jeremy is a very nice guy, immediately gets to work and resolve the issues. This is the second time he’s worked on vehicles for me and each time was an excellent experience. Highly recommend him

Peter

25 years of experience
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Peter
25 years of experience
Scion xA - AC is not working Inspection - West Hills, California
Peter has an awesome personality. Very knowledgeable and friendly. Definitely no BS from him. Very honest.... Will I use him again? Definitely. Will I refer him? Absolutely! Thank you Peter!
Mercedes-Benz ML500 - AC is not working Inspection - Reseda, California
Peter took his Time to check out and diagnose my vehicles problem. I was able to add some Freon and the cooling system is most definitely getting colder. I’m gonna drive it for the next few days as recommended and see where I’m at and go from there. Thank you for your time Peter

Matthew

33 years of experience
991 reviews
Matthew
33 years of experience
Acura RDX - AC is not working - Newport News, Virginia
Matt is always so pleasant to work with. I appreciate his knowledge and attention to detail with my car. Thank you Matt!
Chevrolet Impala - AC is not working - Newport News, Virginia
Matt was on time and during the discussion with him he showed a great deal of knowledge about my a/c issue. I book this repair this weekend and look forward to Matt repairing my car. Thank you Matt

Bryant

12 years of experience
492 reviews
Bryant
12 years of experience
Jeep Patriot - AC is not working - Indianapolis, Indiana
Always great service with Bryant, he explains all he is doing as well as what else needs to be complete. I will be scheduling my next visit from him soon.
Ford Expedition - AC is not working - Indianapolis, Indiana
Second time using Bryant and he was, in both instances, able to diagnose and locate the problem. What I find particularly great is that both issues were very easy and inexpensive fixes. Bryant was very candid about the problem and offered to show me how to fix the issue if I wanted to do it myself. I just had him make the repair, which was done quickly. He also found an alternative part that saved me from having to order it online and wait a few days for the repair to be made. Bottom line, Bryant does what’s right and is honest about what the problem is. Anyone could have told me its a $1,200 repair and I wouldn’t have known differently. Use Bryant if you want honesty and great work.

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