PC Fan Making Rattling Noises (Causes, Fixes)

You may have experienced this before (I know I have) where you are driving on the road, and a slow rattling or whirring noise is coming from the engine, a noise that wasn’t there before. “Sounds expensive,” you think to yourself and keep on chugging, only to realize that one of your tires just popped off.

So, you might be facing a similar situation where PC fan making rattling noises or a CPU cooler. If that is the case, fear not, as I’ll help you find the root cause and show you how to fix it.

Most of the time, a PC fan would make rattling noises when there are loose connections or broken parts. Replacing the fan might help you get rid of this problem.

However, there could be a software issue or a problem with the desktop tower itself. Therefore, to help you get a broader understanding of the issue, we are going to talk about a couple of lengthy topics such as:

• Common hardware-related issues that can cause rattling noises.
• Software issues that are harmful to the fans.

If you are building a new PC or upgrading and you want to know how many fans should a gaming PC have, check this article that we have.

Common hardware-related issues that can cause PC fan making rattling noises

Most of the common causes for a rattling noise coming out from the fans is broken/worn-out parts inside. Sometimes, the issue might go away with a little bit of cleaning and readjustment, and if not, you might have to replace the entire thing.

So in this section, I’m going to list out some hardware-related causes along with how to resolve each of these issues.

Fans Have Collected a Lot of Dust and Dirt

I always recommend blowing out the dust and cleaning your PC at least once a month, especially if you keep your PC on the floor. Depending on your situation (keeping pets and smoking a lot can aggravate this,) a lot of dust and dirt can accumulate in just a week.

When there’s a ton of dust caught up inside your fans, it can prevent the fan from spinning correctly.

The fix is (obviously) cleaning your PC. I recommend doing it yourself, but you can always take it to a professional.

Clearing Out The Dust in a Fan

I always advocate DIY, (Do-It-Yourself) because you learn something new and save up on money. So if you haven’t cleaned out your fans before, here’s a summary of what you need to do.

First, gather your tools: you will need

• a screwdriver and
• a can of compressed air
• a soft lint-free microfiber cloth

An electric blower is also fine, but the can of compressed air is the more convenient option. Also, make sure that you install the small tube that makes it easy for the can to “focus fire” on those tiny spaces.

First, disconnect the fans from the case/motherboard and then unscrew the chassis/housing. After that, blow out the dust using the can of compressed air and use the microfiber cloth to get rid of any stubborn dust particles, but be gentle, especially with the fan blades.

Loose connections: Also, you might have loose connections between the case and the fan, so while you are cleaning out your fans, make sure to tighten the screws and adjust the fan grommets. If the fan housing doesn’t shake or look crooked after you’ve installed it, then you’re good to go.

Issues with the Desktop Tower

Uneven/Tilted Surface: If your PC tower is not sitting on a flat surface, it can cause the blades in the case fans to wobble or bend. Although this is not very common, especially if you’ve fixed the fans correctly, it is always best to keep your PC tower in an upright position on a uniform surface, either on a table or the floor.

Heavy Loads on The PC Tower: Another good practice is to keep your PC tower free from any heavy objects on top of it. Don’t put stack-up books or other devices on top of the tower. Especially if have case fans or radiators at the top of your case. When there’s a lot of weight on the case, the top metal housing tends to deform and drop (usually this happens in cheaper, generic PC cases,) and if there are any fans on the top, the blades will hit the housing and cause unnecessary vibrations and rattling noises. On top of that, it will also cause overheating issues where the vents (at the top of the case) will become blocked.

Lack of proper airflow: Speaking of blocked air vents, make sure that your PC case has enough airflow and ventilation. So when there’s not enough ventilation, the inside of the PC case can get a little toasty, and as a result, the fans will start to work overtime (at faster speeds than usual) to bring the temperatures down. This high-speed operation can also cause a rattling noise, especially on most cheaper case fans and CPU coolers.

Worn Out Bearings or Broken Fan

Another hardware-related issue that may be causing a rattling noise in your fans is either a broken fan or worn-out bearings.

So, in the following guide, I’ll show you how to diagnose a broken fan.

1. First, switch off your PC.
2. After that, unplug and remove the fan in question.
3. If you haven’t already, clean the fan using the steps shown in the previous guide (clearing out the dust in a fan) or use a handful of cotton swabs to clear any dust or dirt.
4. Check the fan blades/chassis for any damage or defects.
5. Also, check the PC case for any damages or deformations.
6. Try rotating the fans manually – along the direction they usually spin – and try to see if it can spin easily without wobbling or rattling.

If you can see that the fan is damaged or difficult to spin, it’s best to replace it. However, if that doesn’t seem to solve the problem, it’s usually an issue with the PC case or the software. (fan is getting instructed to run at abnormally high speeds)

Software issues that are harmful to the fans

It may not be that obvious, but running your fans at the maximum speeds (see also how to use speedfan) all the time – even when it is not necessary – can potentially damage your fans and even reduce their lifetime.

Several software-related issues can cause the fans to spin at unusually high speeds. Most of the time, this is because the CPU is getting overheated.

There are several reasons why a fan might be running at a very high speed. It can be because of:

• Running a lot of resource-intensive apps at the same time. (either with or without your knowledge)
• A malware infection. (which tend to use a lot of processing power)
• CPU air coolers that are pre-configured to run only at the maximum speed. (to improve performance)

If you’ve already checked the hardware and confirmed that there is no problem with the physical components. It’s best to clean out your OS using tools such as CCleaner and Malwarebytes. However, if you want to start again with a clean slate, I recommend formatting your drives and reinstalling windows. You will lose your data, so make sure to back them up.

In conclusion, to summarize what we’ve gathered so far.

PC fans make rattling noises whenever there’s some form of obstruction. These could be dust, dirt, broken/deformed blades, or worn-out/poorly lubricated bearings. Whatever the case may be, it’s best to check if the CPU is getting overheated before starting to dismantle the hardware. 

Conclusion

There are many reasons why a case fan or CPU fan will start to rattle. Most of the time, it’s because of hardware-related issues such as damage to the fans and their surrounding area. Regardless of the issue, monitoring the temperature, and performing periodic maintenance will help resolve most of these issues.