If your Mac is making loud fan noises or other unusual sounds, there are several potential causes you can check. The most common reasons a Mac gets noisy are because it’s overheating, the fans are dusty, the hard drive is failing, or some background processes are using up resources.
You can follow some troubleshooting steps to identify the cause of the noise and fix the problem. With some simple maintenance and adjusting settings, you can likely get your Mac running quieter again.
Quick Fixes
Try these quick fixes first to see if they stop the noise:
- Quit any processor-intensive apps or programs you aren’t using
- Close browser tabs and windows you don’t need open
- Restart your Mac to end background processes
- Check Activity Monitor for apps using a lot of CPU
- Adjust screen brightness to 50% or lower
Often a loud fan or other noises are caused by the system getting overloaded temporarily. Quitting apps, closing browser tabs, and a restart can help free up processing power and reduce the demand on cooling fans.
Check for Overheating Issues
Excessive heat is one of the most common reasons a Mac will have loud fans. As the CPU and components heat up from workload demands, the fans spin faster to provide cooling.
Use these steps to check for overheating problems:
- Open the Activity Monitor app and check CPU usage
- Look at Memory Pressure – if it’s high, reduce memory load
- Check fans with Macs Fan Control or iStat Menus
- Download a temperature monitoring app to check component temps
- Clean dust out of vents and fans with compressed air
- Improve airflow by elevating the MacBook and cleaning the desk
- Lower room temperature if possible
High CPU usage, memory pressure, component temperatures over 80°C, and excessive fan speeds over 4000 RPM indicate an overheating issue. Try the steps above to reduce heat levels.
Reduce Workload and Background Processes
If your Mac is making noise from overheating, start by quitting any apps, programs, games, or browser windows you aren’t actively using. This can significantly reduce CPU usage and lighten the load on your components.
Next, restart your Mac. This will end all background processes that might be using resources and taxing the system. It’s a quick way to clear temporary files and give your Mac a fresh start.
Check Activity Monitor
Open the Activity Monitor utility on your Mac (found in Applications > Utilities). Click the CPU tab at the top and look for any apps or processes using a high percentage of CPU resources. Quit these programs to free up processing power and reduce heat output.
Also look at the Memory tab. If “Memory Pressure” is yellow or red, your Mac is low on RAM which can cause overheating. Try closing some apps and tabs to lower the memory pressure.
Monitor Component Temperatures
Use a system monitoring tool like iStat Menus to check your CPU and GPU core temperatures. Consistently high values over 80°C indicate an overheating problem. Prolonged high temperatures can damage Mac components.
If your MacBook feels very hot on the bottom or makes loud fan noises, overheating is likely the issue. Take steps to improve cooling and reduce workload immediately.
Improve Airflow and Cooling
To help your Mac stay cooler, make sure airflow vents and fans are free of dust buildup. Use compressed air to thoroughly clean the vents and fan blades.
Also elevate your MacBook to allow better airflow rather than using it directly on a desk or table. Make sure the desk area is clean and not obstructing vents.
Lower the ambient room temperature or aim a small external fan at your MacBook to improve cooling.
Check for Faulty or Dusty Fans
If your Mac’s internal cooling fans become faulty or clogged with dust, they can begin to make loud noises or run at high speeds even at low temperatures.
Try these troubleshooting steps:
- Use compressed air to clean fan blades and vents
- Visually inspect fans for damage
- Download Macs Fan Control to check fan speeds
- Check SMC and firmware for updates
- Test fans by stressing CPU and GPU
- If fans seem damaged, seek professional repair
Clean Fan Blades and Vents
Dust buildup on fan blades, heat sinks, and exhaust vents can drastically reduce cooling efficiency. Use short blasts of compressed air to thoroughly clean the inside of your Mac and its fans.
Hold fans in place as you clean them so high air pressure doesn’t cause damage. Be very careful not to dislodge or bend delicate fan blades.
Visually Inspect Fans
If possible, open up your MacBook case and visually inspect the condition of internal fans. Look for any wobbling, damaged, or bent fan blades. Listen for any abnormal grinding or rattling noises.
If you see obvious signs of damage, the fan will need professional repair or replacement. Don’t attempt this yourself as you can easily break sensitive components.
Monitor Fan Speeds
Use an app like Macs Fan Control to check your fan speeds. If fans constantly run at very high RPMs even when CPU and GPU temperatures are low, the fans may be faulty.
Healthy fans will dynamically adjust speeds based on workload and temperatures. Erratic or stuck fans point to a hardware problem.
Stress Test Fans
You can manually stress test fans by loading the CPU and GPU to get component temperatures high. Use an intensive app like a game or video renderer. See if fans behave normally and respond with higher speeds.
If fans seem to lag or not adjust properly as the system heats up, it indicates a fan control issue.
Replace a Failing Hard Drive
If your Mac’s hard drive is failing, it can begin making loud clicking or grinding noises. Other symptoms include:
- Frequent beachballing or long app loading times
- Apps freezing or crashing often
- Files becoming corrupted
- Strange behaviors like disappearing data
If you suspect hard drive failure:
- Back up your data immediately
- Check Disk Utility S.M.A.R.T. status for errors
- Try repairing disk permissions and verifying disk
- Test hard drive by restarting in Safe Mode
- Consider replacing hard drive
Check S.M.A.R.T. Status
Open Disk Utility and click your hard drive. Go to the S.M.A.R.T. status menu to check for any hardware errors reported by the drive.
If you see excessive bad sectors, pending sectors, or hardware failures reported, the drive is likely failing and should be replaced.
Repair Disk Permissions
In Disk Utility, run First Aid on your hard drive and choose to Repair Disk Permissions. Also try verifying or repairing the disk – this can resolve some minor errors.
If errors persist, it indicates irreparable physical damage on the drive.
Test in Safe Mode
Restart your Mac in Safe Mode (hold Shift on startup). This disables non-essential software and loads only the minimum drivers needed. If noises persist in Safe Mode, it confirms a hardware problem.
Replace Failing Drive
Once you confirm a failing drive, shut down your Mac, backup all data immediately, and replace the hard drive. An Apple Genius Bar can replace the hard drive, or you can take it to a reputable repair shop.
Be prepared to erase and restore your Mac from a backup after drive replacement.
Adjust System Settings
Some system settings changes can help your Mac run cooler, quieter, and reduce fan noise:
- Lower screen brightness below 50%
- Turn off automatic graphics switching
- Change Power Nap and wake settings
- Adjust Energy Saver settings
- Enable throttle mode in Macs Fan Control
Lower Screen Brightness
Dimming your Mac’s screen brightness below 50% reduces energy consumption and heat output. This takes load off the CPU and GPU to run cooler.
Turn Auto-Brightness off in System Preferences > Displays > Brightness and manually reduce brightness for maximum heat benefit.
Turn Off Automatic Graphics Switching
Models with dual AMD/Intel graphics can switch modes to preserve power and reduce fan noise. However, automatic switching may sometimes cause stability issues.
Turn this feature off in System Preferences > Energy Saver. Your Mac will stay in the more powerful discrete graphics mode at all times to reduce switching problems.
Change Power Nap Settings
The Power Nap feature lets your Mac run maintenance tasks even when sleeping. This can generate heat and wake fans.
Disable Power Nap or restrict it to do maintenance only during charging to reduce fan activation.
Adjust Energy Saver Settings
In System Preferences > Energy Saver, try these changes:
- Set computer sleep to 10-15 minutes when on battery
- Uncheck “Wake for Wi-Fi network access”
- Set display sleep to 3-5 minutes
Allowing your Mac to sleep faster reduces heat buildup and power consumption over time.
Use Throttle Mode
Apps like Macs Fan Control have a “Throttle Mode” that can slow down CPU/GPU speeds to purposely limit performance. This reduces component temperatures and need for active cooling.
Enabling throttle mode is an easy way to temporarily reduce fan speed and noise when needed.
Eliminate Software Issues
Some software problems can cause excessive fan noise or overheating on a Mac. Try these troubleshooting steps:
- Check Activity Monitor for rogue apps
- Boot in Safe Mode
- Reset SMC and NVRAM
- Reinstall or update MacOS
- Clear application caches
Check Activity Monitor
Open Activity Monitor and sort processes by CPU usage. Look for any apps using an excessive amount of resources. Force quit these programs and check if noise improves.
Some common problematic apps include Adobe/Microsoft programs, anti-malware software, and web browsers with many tabs open.
Boot in Safe Mode
Booting in Safe Mode loads only the minimum essential macOS components and stops third-party apps/login items from launching.
If fan noise is reduced in Safe Mode, a problematic startup item or driver is likely the issue.
Reset SMC and NVRAM
Reset your Mac’s SMC and NVRAM to clear any potential software glitches causing high CPU usage and heat production. This can fix stability issues and erratic fan behavior.
Resetting SMC and NVRAM does not delete any user data.
Reinstall or Update MacOS
A damaged macOS system file could be leading to freezing, crashing, overheating, or excessive fan speeds.
Try reinstalling or updating your Mac operating system in Recovery mode. This will overwrite any corrupted files.
Clear Application Caches
Large cached app data and histories can slow down your Mac over time. Regularly clear cache files, browser histories, iOS backups, and Application Support folders.
This frees up storage space and reduces background processes from cache data.
Conclusion
Loud, constantly running fans or other abnormal noises from your Mac are annoying and can indicate serious problems. With some diligent troubleshooting and maintenance, identifying and fixing the issue is very possible.
Check for software crashes, update macOS, monitor system resources, reduce workload, improve airflow, clean fans, replace failing hardware, and adjust settings. This will likely quiet things down and get your Mac running optimally again.
If you’ve tried all applicable troubleshooting steps with no improvement, seek professional Apple or authorized repair service. A technician can diagnose hardware defects and properly replace any damaged components.