New approach to investigation of combustion engine technical state is vibroacoustics as a diagnostic tool. The main idea of vibroacoustics investigation is following the changes of vibration estimators as a result of engine maladjustment, waste, damages or its failure. Combustion engines technical state diagnostic investigations with use of vibration are very difficult and only few proposed methods could have wider technical use in diagnostics. The combustion engine No. 138C. 2.048 with 1.41. swept capacity, power 55 kW / 75 KM, generally applied to Fiat and Lancia is the investigation objęci. The engine is situated in the investigative laboratory of combustion engines in UTP Bydgoszcz, li makes possible to introduce generated vibration signals as well as the investigation of his adjustment influence on the combustion engine vibration signals change. As a validation of investigation results in this paper is shown presentation of Singular Value Decomposition (SVD) method. The SVD method is the appropriate tool for analysing a mapping from one vector space into another vector space, possibly with a different dimension. Thanks to SVD methods we could decide which symptom given in observation matrix is the best to recognize a set of combustion engine technical state. Relationships cause - consecutive expressing quantitative relation between studied variable symptoms results were qualified using the function of the multiple regression. Introduced in this paper results of investigations are only the part of realized investigative project and they do not describe wholes of the investigative question, only chosen aspects.