Diagnosis of Internal Combustion Engine Performance

This invention provides a non-invasive method for diagnosing performance of a vehicle. The method comprises using a 3-axis accelerometer to perform diagnosis of the performance of an internal combustion engine, the performance of the engine including an engine power loss and one or more flaws associated with the engine mount. The method is also usable for diagnosing deterioration of a suspension system of said vehicle. An apparatus comprising a 3-axis accelerometer for diagnosing performance of a vehicle is also provided. In one embodiment, the 3-axis accelerometer is embedded in a smart phone.