Comment 2 for bug 1704551

I found this solution:

1) create a script inside /lib/systemd/system-sleep with your favourite editor:

vim /lib/systemd/system-sleep/i8kmon

2) copy the following lines in the file (i used /lib/systemd/system-sleep/wpasupplicant as a starting point):

#!/bin/sh
set -e

if [ "$2" = "suspend" ] || [ "$2" = "hybrid-sleep" ]; then
    case "$1" in
        post) systemctl restart i8kmon.service ;;
    esac
fi

3) make the file executable for everyone:

sudo chmod a+x /lib/systemd/system-sleep/i8kmon

4) try to suspend, the fan speed problem should be gone now.