Many ceiling fans have an oil reservoir to keep things running smoothly. You may need to add oil if your ceiling fan:
Is very noisy.
Is making squeaking or grinding noises.
Is not running or rotating smoothly, especially on a low setting.
The best way to check if your ceiling fan needs oil is by checking the oil level. Insert a pipe cleaner into the oil hole. If it comes out clean, your oil reservoir is low or empty, and you need to top it up.