FIELD: chemistry.
SUBSTANCE: invention relates to the field of protecting metals against corrosion and can be used in units of cooling systems, which are subjected to heat testing, or in engines for preliminary running before delivery to a warehouse and/or assembling a vehicle or an engine. A concentrate of a running-in liquid, providing anti-corrosion properties in liquid and vapour phases during the engine running-in, includes ammonium bicarbonate in a synergic combination with, at least one carboxylic acid, suitable for dilution with a solvent. The running-in liquid, ready for an application and providing anticorrosion properties in the liquid and vapour phases during heat testing or the engine running-in, includes ammonium bicarbonate 0.05-5.00 wt % in a synergic composition with, at least, one carboxylic acid 0.2-15.0 wt % and a solvent. The method of protecting a metal surface from corrosion includes preliminary processing of the surface with the running-in liquid mentioned above.
EFFECT: increased duration of a period of anti-corrosion protection of metal units.
15 cl, 1 tbl, 4 ex
