Methods and systems for imparting corrosion resistance to gas turbine engines are disclosed. Existing and/or supplemental piping is connected to existing compressor section air extraction piping and turbine section cooling air piping to supply water and anti-corrosion agents into areas of the gas turbine engine not ordinarily and/or directly accessible by injection of cleaning agents into the bellmouth of the turbine alone and/or repair methods. An anti-corrosion mixture is selectively supplied as an aqueous solution to the compressor and/or the turbine sections of the gas turbine engine to coat the gas turbine engine components therein with a metal passivation coating which mitigates corrosion in the gas turbine engine.