I've got a fan in a laptop that occasionally makes some loud airplane-like noises. It mostly happens about 10 seconds after booting up and lasts for 10-20 seconds.

It also occasionally happens when the computer is running, but very rarely. Interestingly, it does not seem to happen when the processor is being used heavily.

The laptop does not have a discrete graphics card.

The fan is clean.

I'm not sure if the laptop is under warranty, but I trust my own skills much more than I trust the manufacturer (or the shipper).

Before I search for a matching fan and replace it, I thought I would see if it is safe to try any lubricants.

Are there any lubricants that are safe to use inside a laptop?

I don't want a fire or anything that will splatter and cause conductivity issues within the circuitry.

(True story: I once had to use BBQ tongs to remove a friend's new unmodified laptop that caught fire.)