The engine block vibration is the result of the structural response of the engine to its internal forces. The engine malfunctions which affect these forces also affect the vibration signal. The aim of this study was to demonstrate the feasibility of using engine block vibration for diagnosis of combustion faults. A four-cylinder diesel engine was used for this study. In order to detect variations in combustion force (or equivalent cylinder pressure trace), this signal was reconstructed from the engine block vibration. Measured and modified structural responses were used to reconstruct cylinder pressure trace. The modification of structural response was accomplished by processing its magnitude and/or phase. Finally, the method was used to detect and localize a leak in the injector of one of the cylinders.