A customer recently called reporting an Opel Zafira as not running on all cylinders and chugging. A common issue with this vehicle (as with many) would be that the ignition coils have a limited life span and need to be replaced.
We started by removing the spark plugs and on close inspection found soiling and a hair-line crack on the enamel of one of the plugs. Further investigation showed the head gasket was leaking very slightly and the leaked coolant reaching the plug had caused the issue. We replaced the spark plugs and advised the customer of his oncoming larger issue with the head gasket.
A common behaviour when rectifying mechanical issues is taking the easiest and most obvious answers, but often digging a little deeper is the key to correct analysis. An experienced mechanic will notice peripheral signs through noise, wear and contamination and will not simply replace the obvious.
A faulty alternator often leads car owners to replace the battery. Within a short period they return the new battery, complaining that it is faulty. If the initial diagnosis was done correctly a lot of cost and time would have been saved. A mechanic’s experience involves the understanding of the functions of all the cars parts and in the modern vehicle many repairs cannot be considered as simple.
Of course the advances in technology greatly aid today’s workshops and with the many sensors and switches controlling a vehicle through its ECU (on-board computer), it is not possible to operate without diagnostic equipment. However the value of a mechanic’s knowledge and experience cannot be plugged in.
Mostly with mechanical issues it’s not so much the size of the problem, but the size of the solution.