Noisy fan motor, burned out resistor - drilled motor plastic casing to try lubricating bearing - kill or cure

 Have recently had to replace the resistor for the fan speed control, but have also noticed that the fan is very noisy with the bearings squeeling. Given the complexity of changing the fan motor I have gone down a different "experimental" route whereby I have removed the foam pad between the lower edge of the bottom cubby and firewall from which, by lying on my back under the dash, I can see the fan motor case which is a round plastic moulding that contains the motor. I have been able to get a drill in with a 3mm drill bit and drill a hole through the casing through which I have sprayed oil - silicone type as this had a tube on that was long enough to get into the drilling -  that may lubricate the bearings OR kill the motor. I will keep you updated on outcome.