Open letter to South Africa’s students‚ universities and government‚ represented by Minister in the .
LAST week I bent over the engine compartment of the faithful jalopy in my driveway, trying to extricate a dead starter motor, when my neighbour sauntered across the field from where he had been working on his Citi Golf.
He confided that the car had a bad misfire and described how he had identified the affected cylinder by the time-honoured method: with the engine warmed up, let it idle and start removing and replacing the plug wires, one by one. If you remove the plug wire on a cylinder that's operating normally, the idling will deteriorate, from a lumpy misfire to a shaky stuttering as the engine tries to run on two cylinders.
But when you remove the plug wire on the misfiring cylinder, it will make no difference to the idling. I hasten to add that this process of removing plug wires while the engine is idling is not permissible on a vehicle with electronic engine management or a catalytic converter, because it can cause damage to the ignition module.
On the older model Citi Golf it was a safe procedure, and in this case it showed that the number two cylinder was misfiring. What puzzled my neighbour was that when he removed the spark plug from it and, after reconnecting the high-tension wire to it, laid it down with its body touching the engine block, there was a healthy spark at the plug when the engine was cranked on the starter. This meant the misfire was due to some other cause. The next step, I suggested, was to do a compression test on the Citi Golf's engine. A hand-held compression gauge was unearthed on a shelf, and I outlined the routine of a compression test for my neighbour.
Engine warmed up, all plugs removed, accelerator depressed by a helper who will crank the engine on the starter while the main "mechanic" will keep the gauge firmly pressed against the plug hole in the cylinder head and watch the needle jump upwards in jerky steps until it will go no higher, at which point the helper is instructed to stop cranking the engine, and the reading is taken on the gauge.
It wasn't long before I heard the starter on the Citi Golf being called into action. Having wrestled the dead starter motor out of the bowels of the jalopy by now, I walked across to view the results of the compression test. It was as clear-cut a case as I had ever seen: three cylinders exactly on 180 psi., no 2 cylinder on 60 psi Normally this can indicate either a burnt valve or a problem with a compression ring.
I sympathised with my crestfallen neighbour when he told me that the car was sold to him about a year ago with the assurance that the engine had just been overhauled ...