A method for determining a condition of a second component of an engine is disclosed wherein the engine includes at least a first component and the second component. The method includes determining a concentration value of a chemical species in an effluent obtained from washing at least a portion of the first component of the engine, inputting the concentration value of the chemical species in a condition assessment model to update the condition assessment model, and estimating the condition of the second component based on an output of the updated condition assessment model. The effluent used herein includes a wash fluid and the chemical species. The second component is different from the first component and the condition assessment model is a representative of a condition of the second component of the engine.