A method of cleaning a charge air cooler of a turbocharged internal combustion engine, the engine comprising • a cylinder block with at least one cylinder, • at least one cylinder head, • an exhaust manifold arranged in connection with the at least one cylinder head, • a charge air receiver arranged in connection with the at least one cylinder head, • at least one turbocharger with a turbine connected to the exhaust gas manifold and a compressor connected to the charge air receiver, • a high temperature (HT-) charge air cooler and a low temperature (LT-) charge air cooler arranged between the compressor and the charge air receiver, the charge air coolers (26, 28) having heat exchange surfaces, • the LT-charge air cooler being a part of an LT-cooling liquid circuit comprising, in addition to the LT-charge air cooler, at least a central cooler and a circulating pump, • a control unit for controlling the temperature of the charge air in relation to its dew point, the control unit receiving information on the temperature, pressure and humidity of the charge air, and • a first three-way valve provided in the LT-cooling liquid circuit downstream of the LT-charge air cooler, the first three-way valve receiving commands from the control unit to control flow of cooling liquid from the circulating pump to the central cooler either directly or via the LT-charge air cooler, the method comprising the steps of: • sending periodically commands to the three-way valve to throttle direct communication from the circulating pump to the central cooler by forcing such an amount of cooling liquid to flow from the central cooler via the circulating pump to the LT-charge air cooler that results in the reduction of the temperature of the heat exchange surfaces of the LT-charge air cooler below the dew point of the charge air, • allowing water to condense from the charge air on the heat exchange surfaces, • flushing dirt periodically from the heat exchange surfaces of the LT-charge air cooler by the condensed water, and • discharging the condensed water from the LT-charge air cooler. • a cylinder block with at least one cylinder, • at least one cylinder head, • an exhaust manifold arranged in connection with the at least one cylinder head, • a charge air receiver arranged in connection with the at least one cylinder head, • at least one turbocharger with a turbine connected to the exhaust gas manifold and a compressor connected to the charge air receiver, • a high temperature (HT-) charge air cooler and a low temperature (LT-) charge air cooler arranged between the compressor and the charge air receiver, the charge air coolers (26, 28) having heat exchange surfaces, • the LT-charge air cooler being a part of an LT-cooling liquid circuit comprising, in addition to the LT-charge air cooler, at least a central cooler and a circulating pump, • a control unit for controlling the temperature of the charge air in relation to its dew point, the control unit receiving information on the temperature, pressure and humidity of the charge air, and • a first three-way valve provided in the LT-cooling liquid circuit downstream of the LT-charge air cooler, the first three-way valve receiving commands from the control unit to control flow of cooling liquid from the circulating pump to the central cooler either directly or via the LT-charge air cooler, • sending periodically commands to the three-way valve to throttle direct communication from the circulating pump to the central cooler by forcing such an amount of cooling liquid to flow from the central cooler via the circulating pump to the LT-charge air cooler that results in the reduction of the temperature of the heat exchange surfaces of the LT-charge air cooler below the dew point of the charge air, • allowing water to condense from the charge air on the heat exchange surfaces, • flushing dirt periodically from the heat exchange surfaces of the LT-charge air cooler by the condensed water, and • discharging the condensed water from the LT-charge air cooler.