Lenovo X270 excessive heating and fan activity

Open the case, use compressed air to clean out dust from the vents and the CPU fan.
Check heatsinks and thermal pads/paste are connected.
Reassemble and test again
https://www.myfixguide.com/lenovo-thinkpad-x270-disassembly-ram-ssd-hdd-upgrade-options/

Thanks MASQ, will try.

I'd also check if the System is fully updated with System's low level code such as BIOS/Firmware.

Thanks strivoli, I've done that already.

you can install speedfan- to monitor the temps :  http://www.almico.com/speedfan.php
run also a dskchk to be sure about the File system

" I would not dare to disagree with Masq,"
LOL - this is hardly heresy :)

If the dust is that bad it's certainly easier to remove carefully by hand. My experience with compressed air without opening the case is similar to yours which is why I only recommend clearing it with the case open so you can directly see what's happening.

>>  laptop fans are just not built at the standards that they should be  << yep they save every penny they can, and make sure the lifetime does not exceed 3*4 years average