Whenever I hear the word 'stethoscope', I associate it with 'now take a deep breath!'. Thus, quite early in life we come into contact with this 'sound monitoring equipment'. In the automobile technology one could sometimes have been helped by such a device, indeed, it was not available. Never mind, one could help oneself with other means, e.g., the famous long screwdriver, whose grip fits, more or less, well into the ear.

Don't ridicule these methods. You won't believe, just how much you can find out by using them. Of course, in times of longer hair, greater awareness about accident prevention and hidden components, e.g., a motor car-turbocharger, these primitive methods can not keep up with modern technical equipment. A wrong diagnosis can lead to really expensive repairs and to very angry customers.

There is hardly anything more difficult to do than to make a useable analysis of engine sounds. Sure, in the case of a damaged gearbox, if I hear grinding noises when certain operations are carried out, e.g., when down-shifting, the error determination is pretty simple. If however, with a front-wheel drive, e.g., you have to diagnose wheel-bearing damage, the noise often comes from somewhere in the engine compartment and you may assume a different defect or that the damage is on the wrong side.

Stethoscopes are useful because of their ability to amplify sounds and their maximum flexibility as far as noise- or the vibration monitoring of certain components in the field of research and technology is concerned. Because nowadays, workshops have too keep their overheads low, the use of the electronic stethoscope for servicing is often chosen. Battery operted devices are handy and allow access to almost any engine component.

If you are familiar with the wonderfully effective qualities of Piezo-crystals in knocking sensors and modern injection valves, you can also apply this knowledge here. Even very low noises are picked up by the Piezo- transducers and reach you through headsets with adjustable ear-protectors. Thus e.g., sounds from the bearings are greatly amplified and separated from any possible background noise.

There are stethoscopes with long- and short probes, so that also places which are difficult to reach can also be inspected. The stethoscope casing is made of plastic, making it simple and comfortable to work with. The cost-to-perfomance ratio is paticularly important nowadays. The doctor, in former times, certainly paid more for his device. 08/11