Quick Overview
There are a few potential causes if your Mac is making an unusual motor or mechanical noise:
- The cooling fans are ramping up due to high CPU usage or heat
- The hard drive is making noise indicating a potential mechanical issue
- The optical drive is trying to read a disc
- There is dust buildup causing the fans to work harder
The most common reason a Mac makes noise is because the fans are working to cool down the CPU and internal components. This ramping up of the fans usually happens during resource intensive tasks like video editing, gaming, streaming, or running many apps at once.
An abnormal noise could also signal a problem with the hard drive. Clicking, buzzing, grinding, or other odd sounds can mean there is a mechanical failure developing. Back up your data immediately if you suspect the hard drive is the source of the sound.
Other probable causes include a disc stuck in the optical drive, dust buildup causing fans to strain, or even a wire trapped in a fan. Checking for these issues and cleaning your Mac may help resolve an unusual noise. But a noise coming from the hard drive area likely means imminent failure is possible.
Fans Ramping Up from Heavy CPU Usage
The most common reason you’ll hear your Mac’s internal motor make noise is because the cooling fans are spinning faster. Macs are designed to adjust the fan speed based on CPU and system temperature. The hotter the components get, the faster the fans will spin to draw heat away.
When your Mac is under heavy load, such as running multiple apps, games, creative software, or performing OS updates, the CPU has to work much harder. This generates more heat which then causes the fans to ramp up to cool the system down.
You’ll typically notice an increase in fan noise when doing things like:
- Running CPU or graphics intensive applications like Garageband, Photoshop, gaming software, etc.
- Multitasking with a lot of apps open at once
- Performing intensive tasks like 3D rendering or video transcoding
- Streaming/editing 4K or 8K video
- Running many browser tabs and extensions
- Downloading or installing software and macOS updates
- Connecting external monitors which put more load on the GPU
- Using Mac in a hot environment or on soft surfaces that block ventilation
The sudden speeding up and noise coming from the fans is perfectly normal when the CPU is under heavy load. It means the fans are functioning as intended to cool the system. The noise should subside after a few minutes once the task finishes and the components are cooled down.
Hard Drive Failure
Another common source of unusual motor noise in a Mac is a failing hard drive. Hard drives contain moving platters and a mechanical arm that reads and writes data. If you’re hearing noises like clicking, grinding, buzzing, or scraping, the hard drive could be experiencing problems.
Specifically, some common hard drive failure noises include:
- Clicking – Usually signals the arm is making contact with the platter or there is a problem with the spindle motor.
- Grinding -Indicates the read/write heads are touching the platter surface, usually due to impact damage or instability.
- Scraping – Friction between the heads and platters, often due to contamination or misalignment.
- Buzzing – Motor that spins the disks has become faulty.
- Screeching/shrieking – Seen with motor or bearing failures as metal components scrape together.
- Chirping – May signal degraded components leading to eventual failure.
Hearing any odd or loud mechanical sounds from the internal hard drive is not good. The drive will likely continue degrading until it fails completely. Immediately back up any important data and replace the drive as soon as possible.
It’s also possible for sounds to come from other rotating storage devices. For example, fan noises, clicking, or buzzing could originate from a failing Fusion drive, SSD, or HDD in an external enclosure. Troubleshoot to isolate the sound if possible.
Optical Disc Drive Noise
If you hear whirring, spinning, grinding, or buzzing noises coming from the lower right side of a MacBook Pro or iMac, the likely culprit is the optical disc drive attempting to read a disc.
The optical drive contains a motorized spindle that turns the disc, along with a laser head that tracks across the surface to read data. Noisy symptoms can occur if:
- The drive is trying to read a disc that is dirty, scratched, or damaged.
- A disc is stuck and the motor continues trying to spin it.
- The drive components have become worn out or unstable.
- A foreign object got lodged inside the drive bay.
- The spindle motor or laser head is failing.
If a disc is not being read properly, the optical drive will make repeated efforts to read it, causing increased noise in the process.
Try ejecting any discs by holding down the eject button for several seconds. If the noise persists even without a disc inserted, the drive itself may be failing. If the disc won’t eject, a paperclip inserted into the manual eject hole can force it open.
As a last resort, you can disconnect the SATA cable from the optical drive to see if the noise goes away. If so, replacement of the optical drive would be the solution.
Dust Buildup Causing Fan Noise
Dust accumulation inside your Mac can force the cooling fans to run faster and louder. This is because the dust prevents proper ventilation through heat sinks and air vents.
Some common fan noises that can indicate dust buildup:
- High pitched whining
- Rumbling or buzzing
- Cyclical pulsing patterns
- General louder airflow
To eliminate dust as the cause:
- Use compressed air to blow out vents along the sides, back, and bottom of the case.
- Check and clean fan blades and air channels inside the computer.
- Replace any clogged air filters if present.
- Consider having an Apple Authorized Service Provider deep clean the inside if needed.
Prevent excessive dust by using your Mac in a clean environment and giving it adequate ventilation room around the sides. Also check for any pets or cigarette smoke contributing to dirt buildup.
Fan Making Rattling, Buzzing or Grinding
If you hear a rattling, buzzing, grinding or other mechanical sound, it could indicate an issue with the fan itself. For example:
- A wire or cable may be loose and vibrating against the fan.
- The bearings that allow the fan blade to spin are worn out.
- Blades are warped or brushing against the housing.
- Fan is unbalanced and wobbling.
- Debris built up on fan blades throwing off rotation.
Try cleaning around the inside of the vents with compressed air to remove any debris on fan blades.
Check visually that no wires are being struck by the fan motion. Also listen closely to isolate the fan making the noise by stopping each one individually.
But the fans are difficult to repair and usually the whole assembly would need replacement if a bearing or motor has failed. Have an Apple authorized service shop evaluate and replace the fan if needed.
Loose Internal Components
If you hear buzzing, rattling, or other shaking noises, a loose internal component could be the cause. Motions from typing on the keyboard, tapping the trackpad, or normal handling can cause things to shift and vibrate.
Some possibilities include:
- Hard drive – Secured in a bracket but still able to move slightly if screws are loose.
- Optical drive – Can also work loose and rattle in the chassis.
- Wires – Power cables or flex cables brushing against parts.
- Fan blades – Rubbing on housing or frame.
- Heat sink – Not tightened properly to CPU.
- RAM – Not fully seated in the slot.
- Battery – Jiggling in the bay.
- SSD – Loose if installed in the optical bay.
Opening up the Mac and checking for anything loose that’s making contact can help resolve these types of noises. Just be extremely careful not to damage any delicate components whenever working inside. Tightening down specific hardware or securing the component properly again should stop any rattling or shaking.
Isolating the Sound
It’s important to isolate exactly which component is making the unusual motor noise before proceeding with solutions. Here are some methods:
- Press your ear against different surfaces on the Mac to pinpoint the location.
- Turn off or disconnect fans and drives one at a time until the sound stops.
- Use a mechanics stethoscope or tube to amplify and isolate the sound.
- Play different audio tones through the speakers to change the noise pitch.
- Compare to audio recordings of known component failures (hard drive, fan, etc).
Also correlate the circumstances in which you hear the noise:
- Happens when accessing certain files – Likely disk drive related.
- Only occurs when system is under heavy CPU load – Probably fan ramping up.
- Sound starts when optical disc inserted – Points to disc drive.
- High pitched whine heard constantly – Could be power supply issue.
Take notes of your observations so you can better pinpoint the sound to a specific component. This assists troubleshooting and getting the proper repairs done.
External Device Sounds
Keep in mind noises could emanate from external equipment connected to your Mac as well. For instance:
- External hard drives spinning up and making scratching or grinding sounds.
- Vibrations from accessories plugged into USB ports.
- Noisy power adapters if dust has collected internally.
- Fans and drives in external enclosures.
- Motors or gears from mobile devices docked to USB-C/Thunderbolt.
Try disconnecting one external device at a time to isolate the sound. Determine if the noise stops when removing a certain peripheral. This can indicate if the sound is due to a faulty external component rather than something inside the Mac itself.
Liquid Spill Damage
One other possibility is liquid spilled onto or into your Mac. Things like water, coffee, soda, juice, etc can cause immediate damage to internal hardware. Electrical shorts and corrosion can develop quickly.
Signs of liquid damage include:
- Visible staining around ports, vents or seams in the case.
- Distorted or buzzing sounds from speakers.
- Flickering/scrambled screen visuals.
- RAM slots not recognizing installed memory.
- USB and other ports not working correctly.
- Fan noises, grinding, or clicking coming from components.
- System random shutdowns or failures to boot.
If you suspect liquid got inside your Mac, urgent action is required. Dry out the machine as best as possible, open it to look for any corrosion, and have a repair shop assess the extent of the damage. Liquids can cause electrical shorts, rust, and permanent component failure if not addressed quickly.
Software Causes
While most Mac motor noises originate from hardware components, occasionally software can artificially cause such sounds too:
- Apps – Certain music, video, or game apps may intentionally play mechanical sounds like engine noises for effect.
- Audio feedback – Software bugs can sometimes cause audio feedback loops of distorted noises through the speakers.
- Fans – Malware or system corruption could crank up fans unnecessarily.
- Startup – Corrupted boot software may cause fans to rev loud right after clicking the power button.
Try isolating whether the noise only happens when using certain apps. And check if safe mode stops the sound, which points to some system file rather than hardware being the issue.
Reinstalling macOS or repairing disk permissions can clear up OS file corruption that leads to anomalous fan behavior in some cases.
External Speakers
Keep in mind motor noises could also come from external speakers connected to your Mac rather than from inside it.
Causes may include:
- Faulty power adapter making buzzing or whining sounds.
- Damage to speaker cones or internal components causing rattling.
- Music or audio itself contains mechanical sounds (some songs or sound effects use such noises).
- Audio system feedback if microphone is picking up speaker output.
- Poor quality cables picking up interference.
Test whether the noise persists even without speakers plugged in. Try different speakers to isolate the issue further. This can help determine if the sound is due to a problem with the external speakers themselves.
Preventing Loud Fan Noises
While occasional fan noise is expected with a Mac, you can take some steps to reduce loud fan activities:
- Avoid resource heavy multitasking that heats up the CPU.
- Close any apps not actively in use.
- Make sure vents have clearance and airflow is not blocked.
- Use your Mac on a hard flat surface rather than on a rug or bed.
- Keep your Mac out of direct sunlight or hot ambient environments.
- Run the Mac in clamshell mode with external display to reduce heat.
- Use macOS software tools like Turbo Boost Switcher to limit CPU usage.
- Adjust fan speed curve with Macs Fan Control or similar utilities.
- Clean out internal dust buildup with compressed air.
Following general dust and heat precautions will reduce the need for loud fan activities. But some noise during intensive tasks is still expected and normal.
Back Up Your Data
If you suspect a hardware issue like a failing hard drive or fan, immediately backup your important files as a precaution.
Cloning the entire drive with SuperDuper or Carbon Copy Cloner are good options. You can also manually drag documents, photos, videos, music, and other personal files to an external hard drive or cloud storage.
Backing up ahead of time ensures you won’t lose any data in case a component stops working entirely. You can then get repairs done without worrying about permanent data loss.
When to Seek Repair Service
In some cases you may be able to resolve motor noises yourself through cleaning or proper component reseating. But it’s generally best to have an Apple authorized service provider evaluate the problem, especially for internal hardware issues.
Seeking professional Apple repair is recommended if:
- The noise indicates failure of a core component like the hard drive, cooling fans, power supply etc.
- You lack the technical skill or tools to open the Mac and perform repairs safely.
- The sound persists after trying basic troubleshooting steps.
- Your AppleCare warranty or coverage is still active.
- Visible damage or liquid spills may have occurred.
Apple authorized technicians have proper repair training, access to official Apple parts, and will safely diagnose issues. This also ensures any repairs done will maintain the Mac’s warranty coverage.
For more minor noises, you may be able to fix the issue yourself with some tinkering. But critical component noises are best handled by professionals to avoid making the problem worse.
Conclusion
Unusual motor noises coming from a Mac are typically the result of fans spinning faster, a failing hard drive, or other internal hardware issues. By methodically isolating the sound and when it occurs, you can better identify the underlying cause. Fan noises when the CPU is hot are normal, but scratching and grinding sounds can signal a component about to fail. Seek professional repair help for critical issues affecting core components like the hard drive, RAM, or cooling system. Catching and addressing problems early can help prevent catastrophic failures down the line.