Previously, the fan would be completely silent unless I ran an intensive application (e.g. a game). Now, whenever Windows starts, the fan kicks into high speed within a few minutes even if I am not running anything intensive. It is loud enough to create a persistent noise.
I took off the back panel so that I could clean some dust out of the grills that might have been blocking the fan intake, but I don't see any difference afterwards as the fan is still noisy after a startup.
Laptop feels cold to the touch as well.
There could be several reasons for this including
1. A clogged fan and heat sink (dust and lint build up)
2. Worn out bearings
3. Version of BIOS or missing / corrupt power management software
1. Check the fan and heatsink for dust build up. As needed, clean thoroughly, using canned air to remove dust build up. See related article on cleaning an older N100 model - the steps are similar although the fan cover and mounting screws may vary somewhat on other Idea series systems.
2. Oil or replace the fan. If the system is in warranty, and the fan is clean, but is noisy or there is a mechanical sound like there is interference or the blades are rubbing on the housing, please contact support. If the system is out of warranty and you have already cleaned the fan, yet it is much louder than it used to be, some customers have reported that they were able to disassemble the fan, lift out the blade, shaft, magnet assembly and applying a small drop of extremely light oil - sewing machine oil or 3 n 1 light oil, or graphite lubricant (use either oil or graphite by do not mix) to the hole in the center of the motor assembly. Reinstall the blade assembly and housing. Reinstall fan into the system. Often this quiets the fan operation for a period of time.
3. Update your BIOS to the latest version and ensure power management software is installed. Sometimes entering BIOS and selecting the option to reload defaults may help. If you have performed a clean Windows install, download and install the Lenovo power management software as it can optimize fan operation.