Q: Why is my Mac hot and noisy?

Try restarting your Mac.

Try Safe Boot:

- Shut down your Mac

- Wait until your computer turns off and after that press the Power button

- Right after you hear the startup tone, press and hold the Shift key

- Release the Shift key when you see a grey Apple sign and the progress bar below this sign

- After your Mac boots up, restart it as you usually do.

If this doesn't help, follow the instructions below:

- Shut down your Mac

- Wait until your computer turns off and after that press the Power button

- Right after you hear the startup tone, press and hold the Shift key

- Release the Shift key when you see a grey Apple sign and the progress bar below this sign

- Once you see Desktop, start a Disk Utility scan to detect and repair file system errors (don't forget to choose your main hard drive)

- Click on Verify Disk and then, if asked to fix problems, on Repair Disk

- After this, click on Verify Disk Permissions and then on Repair Disk Permissions

- After the process is finished, shut down your Mac and turn it back on after about 30 seconds

Apart from that, take a look at this Apple article and follow the instructions on Resetting NVRAM shown there: How to Reset NVRAM on your Mac - Apple Support

Try resetting the System Management Controller: https://support.apple.com/en-us/HT201295

Run this test and post its results here.

http://www.etresoft.com/etrecheck

Hope this helps!

Check Activity Monitor to see if any application is using a lot of resources:

https://support.apple.com/en-us/HT203184

Run an Apple Hardware Test:

https://support.apple.com/en-us/HT201257

Note that an error free AHT is not definitive.

Ciao.

Very good. 

Ciao.