trou all fridges have alittle bit of oil in the system, it actually migrates with the gas around the system, usually there is enough in the system even if you have a gas leak, take no notice of the amateurs. the compressor is a little piston thingie, usually 25 cc or there abouts and needs the oil to lube it. if it is a system with freon 134 in you can buy small cans of gas and a refill connection off ebay and do it yourself. stu