The bearing inside the fan belt roller sensor can become dry and rusty over time and starts to squeak. It usually starts to make the squeaking noise only in the morning but eventually the problem will get worse and the squeak will remain constant. I believe moisture plays a big part on the cause of this problem, and when the bearing gets dry it will starts to squeak. Most often the squeaking noise has been blamed on the belt, but the roller is also one place to check for the source of the noise.
Tools required for this DIY are:
There is only one 5 mm allen bolt that holds the fan belt roller in place. To remove the 5 mm bolt I strongly recommend using a 5 mm allen socket to remove this bolt. Because of the limited space you have to work with you will be tempted to use an allen key, but I strongly suggest against this idea.
Prior to the removal of the fan belt roller
I had to make a slight modification to my 5 mm allen socket in order for
the tool to fit in the confined space. As you can see from the picture
the allen shaft on the allen socket is quit long. I had to cut a
section of it off in order for it fit into the engine bay with the ratchet
Be very careful once the bolt has been loosen to take the bolt off first before you remove the fan belt roller. Because if you are not careful and bolt will fall off and you will have one heck of time to fish it out from under the crank pulley.
In my case I used some "Break Free" lubricating oil to soak the roller bearing assembly with oil. "Break Free" oil can be picked up from many firearm shops, it is primary used to provide lubrication and protection to firearms.
I poured some oil in the bearing area and had it soak over night before installing the roller unit back on to the car.
Reinstall the fan belt roller and you are
done. The squeaking noise will not come back for sometime.