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Scope Scope Scope! Cylinder testing

Thursday 4th June 2015
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In the past mechanics have muddled by with just a multimeter as their trusted diagnostic friend. No longer is this the case.

Every day on the helpline we are asked to help with ever more complicated problems on modern vehicles, only to discover that the mechanic has only a multimeter to complete these tasks. Often trying in vain to test high speed signals on sensors and actuators only to find themselves running around in circles. Mission Impossible.

One good example is in cylinder testing, which gives a picture of the mechanical events occurring within the cylinder. Not just compression pressure, but timing of events during the whole engine cycle from TDC to TDC. This can spot valve timing errors, compression issues, and even time injection and ignition events, to degrees of engine rotation, also  pressure increased in cylinder due to a restricted DPF systems . The trace above is an example of a stretched timing chain on a Micra. All these tests, and many more, are possible with a pressure transducer attached to an oscilloscope.  

We often get emailed scope traces sent to the helpline for checking. This is a very helpful service which can lead to a faster and better diagnostic answer to many problems encountered every day in modern workshops.

For your risk-free trial on the eXponentia Technical Helpline, ring us on +353-(0)1-905-9500.