door was making very loud noise, i put oil and it stopped making loud noise. How?
The loud noise was likely caused by the door hinge or other moving parts rubbing against each other and creating friction. This friction was generating a lot of heat, which was causing metal parts to expand and warp slightly, leading to the noise.
When you applied oil to the hinge or moving parts, it acted as a lubricant, reducing the friction between the metal parts. With less friction, there was less heat generated and the metal parts were able to move more smoothly against each other. This eliminated the warping and allowed the door to move more easily and quietly.