What Color Is AC Compressor Oil

What Color Is AC Compressor Oil

Oil is a crucial component in the AC compressor. We can determine the quality of the oil by its color. So, what color is AC compressor oil?

The normal color of the AC compressor oil ranges from clear to dark brown. AC compressor oil can be evaluated using a color chart. The light color indicates good condition, while the dark color suggests contamination. Change the oil if it matches the dark shade.

I did deep research to find the answer to this when I checked the oil of my AC compressor. In this article, I will explain how I checked the AC compressor oil and how to determine the oil quality by its color. Let’s dive into the topic, what color is AC compressor oil?

What Is the Need for AC Compressor Oil?

AC compressor of a car

First of all, let’s understand the need for oil in the AC compressor. Mainly, there are 2 roles for the oil in the AC compressor.


Pistons, bearings, and valves are the moving internal components of the AC compressor. They move at a very high speed under high pressure. AC compressor oil works as a protective film for them. So, the metal-to-metal contact wear reduces.

Heat Dissipation

As with any other compressor, the AC compressor also generates a high amount of heat during operation. Oil helps to reduce this heat. So overheating is prevented.

What Are the Types of AC Compressor Oil?

Different vehicles use different types of oils for the AC compressor. However, the most common types of AC compressor oils are mineral oil and synthetic oil.  

AspectMineral OilSynthetic Oil
UsageUsed as AC compressor oil in systems with R-12 refrigerant.Mostly used in modern vehicles with R-134a refrigerant.
Environmental ImpactHigher environmental impact due to R-12 usage.More environmentally friendly.
LubricationProvides good lubrication.Provides better lubrication.
Thermal StabilityHave limited thermal stability.Provides better thermal stability.

What Are the Problems Associated with Low AC Compressor Oil?

Low oil levels lead to various problems in the AC compressor and the overall air conditioning system. Here are the problems associated with low AC compressor oil.

Compressor Overheating

As we discussed above, the primary task of the oil is to dissipate the heat from the compressor. So, what happened to the compressor running on low oil? Yes, you are correct. Overheating happens due to increased friction, which also results in increased wear.

Poor Lubrication

Insufficient oil means that the compressor’s internal components, such as pistons, bearings, and valves, do not receive proper lubrication. This results in increased wear and tear on those parts, and the compressor’s lifespan is reduced.

Air Leaks

The oil acts as a sealant for the AC compressor. Low oil levels compromise these sealings and lead to air leaks into the system.

Reduced Cooling Efficiency

The compressor can’t efficiently compress the refrigerant with low oil levels. Then the vehicle interior will not receive enough cooling.

Increased Compressor Noise

You can hear unusual noises from the AC compressor if it runs with low oil.

Higher Energy Consumption

A poorly lubricated compressor has to work harder to compensate for the lack of oil. So, it results in high energy consumption and low mileage.

System Contamination

Low oil levels lead to the accumulation of debris and contaminants in the compressor. This can further impair the compressor’s performance.

Compressor Seizure

Finally, if you run for a long period with low oil, it results in the AC compressor seizing. A seized AC compressor has a huge impact on the vehicle’s engine. So, you have to get an immediate action on the AC compressor. If you don’t need AC anymore, you can bypass the compressor. Manually disengage the AC compressor clutch as a temporary solution.

How To Check AC Compressor Oil?

To check the AC compressor oil color, you should know how to check the AC compressor oil. This is how I checked the AC compressor oil.

First, I started the car.

Then I turned on the AC and reduced the blower speed.

I waited 1 minute to allow the pipe leading to the low-side valve to warm up.

Next, I attached the oil phase tester to the low-side valve.

I pressed the oil phase tester three times. Then I compared the oil phase tester color with the provided color scale.

How To Compare the AC Compressor Oil Color with The Color Scale?

Pouring oil from AC compressor to a small plastic container

I will briefly explain it as a short step-by-step guide.

Step 1: Get the Color Chart

Get the color chart provided with the tool. It has different color shades indicating the oil condition.

Step 2: Compare the Colors

Compare the color of the oil phase tester with the color on the chart. The light color suggests the oil condition is good. The dark color means the oil is contaminated.

Step 3: Take the Necessary Steps

If the oil color matches a shade on the color scale that indicates poor condition, you should change the oil in the AC compressor.

My Oil color was light green. It means the AC compressor oil is in good condition.

Then I checked the wetness portion of the oil phase tester. Only a small portion was wet. It indicates a low oil level. So, I had to add oil to the AC compressor. As it is a complex task, I went to a professional.

Tip: If the oil level is sufficient, the entire material should be wet.

What Color Is AC Compressor Oil?

So, what color is AC compressor oil?

As I explained above, the normal color of the AC compressor oil is pale green. If the AC compressor oil has a dark color, it should be changed.


What is an AC compressor clutch?

The AC compressor clutch is a crucial component of an automotive air conditioning system. It is responsible for engaging and disengaging the AC compressor from the engine’s power to control the flow of refrigerant through the system.

Can a car AC compressor leak freon?

Yes, the car AC compressor leaks freon due to corrosion of the AC system components, a problematic AC compressor, damaged refrigerant lines, and a stuck clutch.

Can I replace my car AC compressor myself?

Yes, you can replace the AC compressor in the car yourself with proper guidance. If you are not familiar with those tasks, it’s best to consult a professional.

How much to replace a car ac compressor?

In 2023, the average cost to replace a car AC compressor is $1200. This varies depending on the vehicle model and the labor cost.


I hope you understand what color is AC compressor oil. You should regularly check the AC compressor oil to keep the compressor at optimal performance.

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