How to Clean Dust and Fan on MacBook

If kernel_task is using a large percentage of your Mac CPU

I noticed that kernel_task would frequently reach 100% and cause my Mac to lag, but it is a System process and there’s nothing I can do about it.

According to Apple’s documentation If kernel_task is using a large percentage of your Mac CPU:

In other words, kernel_task responds to conditions that cause your CPU to become too hot, even if your Mac doesn’t feel hot to you. It does not itself cause those conditions. When the CPU temperature decreases, kernel_task automatically reduces its activity.

This means that because the CPU is too hot, even if it doesn’t feel hot to you…

Also, kernel_task isn’t the main culprit. Its usage will automatically decrease when the CPU temperature goes down…

I also found out that you shouldn’t charge your MacBook on the left side.

Here’s why you shouldn’t charge your MacBook Pro on the left side

While charging the MacBook Pro and having peripherals plugged in to the left-hand ports, the device’s ports can get hot; for some reason, this can result in kernel_task going a bit haywire and using up a whole boatload of system resources.

However, even after switching to charging on the right side for a few days, it still reaches 100% after a while.


Suddenly, I thought maybe it needs cleaning.

How to Clean MacBook Dust & Fan

I Googled and found out that you can do it yourself.
Mine is from 2016 and the warranty has already expired.
Otherwise, according to the Mac Warranty, it would be voided if I do it myself.

This Warranty does not apply:

  • (c) to damage caused by use a third-party component or product that does not meet the Apple Product’s specifications

Tools 🔧

  • Pentagonal screwdriver
  • Dust blower, small brush
  • Discarded credit card 💳


  1. Unscrew the screws
  2. Create a small gap on the side
  3. Insert the unused credit card 💳 and slide it along the blue arrow direction shown in the diagram
    1. You will hear a click sound
    2. In Figure 2, you can see a row of four card slots along the middle horizontal line
    3. Be careful not to break anything (hopefully 😓)
  4. Slide the 💳 symmetrically on the right side as well
  5. Then, pull horizontally with force following the red arrow
    1. Figure 2 shows slots above the fan
    2. So you need to exert horizontal force, gently pulling left and right ↔️ symmetrically
  6. The back cover will open

It is indeed extremely dirty.

After cleaning the dust, kernel_task doesn’t appear as often, and the 💻 is revived.
I suddenly feel like my 2016 MacBook can last for another 5 years. 👨‍💻

Translated by gpt-3.5-turbo