How to Clean Evaporator Coil Without Removing It – 7 Steps

When your car’s AC evaporator coil gets too dirty, it can adversely affect the performance of your car’s AC. So it’s a must to clean it periodically.

Evaporator coil cleaning is not too complicated. Any car owner can even easily do it themselves without taking out the entire system. Although it may require the quick removal of some parts and possibly drilling a hole, cleaning it can simply be done by spraying an AC evaporator coil cleaner on it and rinsing it.

Read further to know more details on how to clean evaporator coil without removing it.

What You Will Need to Follow this Tutorial

You will only need a few things to achieve a clean evaporator coil. See them below:

1. Screwdriver or Electric Drill

Cleaning evaporator coil without removing it would entail making an access point from where you can clean the evaporator core. There are three options for doing so.

The first two options, which are removing the blower fan and taking out the resistor block, would require the use of a screwdriver. While the third option, which is creating a hole between the blower fan and evaporator case with an electric drill, would require an electric drill.

2. Evaporator Coil Cleaner

Most evaporator coil cleaners usually come in a spray bottle with an additional hose and are foam-based. The cleaner’s spray form along with its additional hose makes applying it easier. And the cleaner’s foaming action allows the cleaner to stick to surfaces while it effectively works on removing dirt, grease, and debris from the evaporator coil.

3. Spray Bottle or Garden Hose

For rinsing the evaporator coil, you can use either a spray bottle or a garden hose. But much caution must be observed if you’re going to use the garden hose.

4. Towel, Blow Dryer, or Hair Dryer

A towel, blow dryer, or hairdryer will come in handy for drying the evaporator core.

Step by Step Instructions

Maintaining the cleanliness of car AC evaporator coils isn’t too complicated of a task. There’s no need for car owners to send their car to a detailer, as they can easily clean evaporator coils without removing the entire system. Find out how below:

Step 1: Remove the Glove Box

Since in this process, you would not be removing the entire system, you will only remove the glove box. The way glove boxes are designed varies among the different car models.

Some glove boxes can just easily be removed by opening them up, pushing their edges together, and pulling them out. While others would require more steps like detaching a cable at the side that supports the glovebox, detaching arm support at the side, unfastening some screws, etc.

Step 2: Access the Evaporator Coil

The evaporator coil can be found by the firewall separating the engine compartment and passenger area. In order for you to clean evaporator coil in car, you would have to make a way for you to access the evaporator coil. There are three ways you can access the evaporator coil.

The easiest means to get access to the evaporator coil would be to remove the blower fan. You can do this by disconnecting the terminal that is attached to the blower motor by pushing the plug inward and pulling it out. Then you would unfasten the three screws that secure the blower motor to the dashboard’s underside.

Or another option that you could do to get quick access to the evaporator coil is by removing the resistor block Just a heads up when removing the resistor block, if it had been working moments before you will do this task, allow it to cool for at least five minutes.

The first step for removing the resistor block is to disconnect the negative battery cable and when setting it aside, make sure it’s placed somewhere it won’t get in contact with metal. Then unfasten the two screws that hold the resistor block onto the housing and keep them somewhere safe to avoid losing them.

But if you are still not able to access the evaporator coil even after removing either aforementioned parts, what you can do to finally access the evaporator coil is to drill a hole measuring ⅜ of an inch between the blower fan and evaporator case.

Just be very careful in doing so to avoid damaging other parts. This third option is a risky task that requires much caution, so this should only be the last resort when necessary.

Step 3: Spray the Cleaner on the Evaporator Coil Through the Access Point

Attach to the foam-based evaporator coil cleaner, spray the additional hose and insert the hose through the access point you created. Then thoroughly apply the cleaner to the entire evaporator coil. Let the evaporator coil soak in the cleaner for thirty minutes to allow the cleaner to take effect on the evaporator coil.

Once applied and left to soak the evaporator coil, the foam cleaner will later become liquid and flow through the drain openings. That would also help get rid of any blockage in the drain.

Step 4: Rinse the Evaporator Coil

The evaporator coil would then be rinsed after the cleaner has done its job with its foaming action. There are two ways you can rinse the evaporator coil.

One is by giving it a light spray only, using a garden hose. But you have to be careful not to let the water fill up the inside of your car. You may ask someone to help check on the water.

The other way is by spraying clean water on it using a spray bottle. You can do this method instead if you don’t feel comfortable with using a hose.

Step 5: Dry the Evaporator Coil

To dry the evaporator coil, you can towel it dry. Or you can use a blow dryer or hairdryer.

Step 6: Put Back the Blower Fan or Resistor Block or Seal the Hole You Drilled

After finally finishing cleaning and drying the evaporator coil, it’s time to put back in place the blower fan or resistor block that you removed earlier to access the evaporator coil. Just reattach the plug you removed from it then screw it back in.

Or if you have drilled a hole between the blower fan and evaporator case, you would have to seal the hole with RTV silicone.

Step 7: Put Back the Glove Box

Once the evaporator coil is finally clean and whatever removed part from the dashboard’s underside has been returned or the hole drilled has been sealed, you can then do the last step. And that is to put back the glove box, which you can simply do by doing the glove box removal in reverse.

Furthermore, please take a look at some guides on engine care below: 

• Cleaning a Car Engine Bay without Spending Too Much Time
• A Detailed Guide on Cleaning the Inside of an Engine

Conclusion

Dirt accumulated on the evaporator coil can affect your car AC’s cooling. In order to enjoy the best cooling performance from your car AC, one of the essential maintenance tasks you need to do periodically is to clean the evaporator coil.

Trying to figure out how to clean evaporator coil without removing the system to do it yourself is a smart move. Now you’ve found out how, the next thing to do is to finally apply the steps shown in this tutorial. But before you do, please give this article a like and share it if you found it helpful.