My air conditioner all of a sudden started making a loud noise when it turns on. The noise continues while the A/C is running.When the A/C cuts off it sounds almost like the fan needs to be oiled. It sort of makes a loud noise when the fan is cutting off like a slow clinking while it is cutting off.-Can the fans be oiled or do they usually need to be. I opened up the A/C unit but I am unable to reach the fan part myself. I suppose this is not part of the usual a/c tune up your suppose to do yearly.Thank you-Cheryl

Actually if the motor is not self lubricating it should be oiled ever year or two.
You would almost have to be there to tell exactly what the noise is.

If you can move the shaft of the motor side ways (side to side) it is worn. If you can move the shaft up and down just a little it is OK.

It is also possible you have a cracked blade where it rivets to the hub area or the hub is loose on the shaft.