My fridge started making a loud noise as if gas was escaping which continued for some time after I turned it off. When turned back on, there was a high frequency whistle which alternated with the gas sound for days. I eventually worked out the motor might be overworked and checked the seals which looked OK.
I cleaned the rubber seal and metal doorframe with Cif and it's been fine since - I think there was a build up of gunk around the seal which let air in and so the motor ran continuously and overheated.
