Optimising the processes within an internal combustion engine is becoming increasingly important in this day and age. A whole series of measurements is vital for engine management purposes. The temperature of the exhaust gas is one important source and is recorded using a thermocouple within the manifold. To check the way it is attached, it is necessary to examine the propensity to vibrate, as well as the mechanical rigidity of the structure. This is an application where the blue laser comes to the fore.