Laptop noisy sound - fan or HDD?

I've experienced some strange noisy sound in my laptop. I can't definitely tell it's from the fan, but I think so because HDD failure sounds are different.

The laptop is Dell Latitude E6410, its hard disk and its cooling fan is next to each other so I can't distinguish where the sound comes from.

Here is the sound: https://youtu.be/3ud-5u_jJnk, sometimes it runs continuously.

It's not overheating. I've checked the temperature and it's around 50 - 60 Celsius. It's maximum temperature is around 100 ºC, so it is not the cause of heat.

I also tried disassembling the fan but it has two plastic weldings which I can't open. I tried using a blower and using a brush to clean out dust but the sound continues.

Is it definitely the fan? Then should I replace it or can I try something else?

I have the exact same laptop model and the exact same issue. It is the fan blades rubbing against the fan's housing. I was able to open up the fan assembly and pull out the fan by the blades, as it was on a spindle. I used a needle to put some mineral oil into the shaft to lube it. I noticed when removing the needle, there was dirt that stuck to the needle. This was just enough to push the fan's spindle out of alignment to cause it to rub. Once I buttoned everything up, it worked. It has also worked perfectly, running 24/7 for several years, as a media center laptop connected to the TV in my bedroom.

Im assuming the plastic welds are over the screw holes. There was a another SU post about a similar problem, who showed pictures of his laptop. The fan assembly was the same as mine, except there was plastic blobs where the screw holes were. Since the fan is not working right, there is no reason not to try to remove the plastic welds. There may or may not be screws under them. If the welds go into the screw holes, you might have to use some glue to put the cover back in place. But cleaning the shaft and using some oil should solve the issue.

That would be your fan lol. It’s making that sound because the fans bearing has gone bad. Just replace the entire fan and you’ll be good to go.

Can always use the CHKDSK tool on Windows or smartctl on linux to check the disk health. There are some tools to slow or speed up the fan as well which could help further to narrow it down.