CAR CLINIC | Is the classic 'tune-up' an outmoded practice?

Fifty years ago it was common practice to take your car to a workshop for a “tune-up” whenever you felt there was something wrong with it. Had the car become hard to start in the morning? It needed a tune-up. Did it begin to jerk under load? It should go for a tune-up. Had it become very heavy on fuel? A tune-up would take care of it. A tune-up was the great cure-all.  

There was a good reason why a tune-up usually produced the desired result, at least temporarily. In those days the vast majority of cars had an ignition system based on contact-breaker points and the fuel supply was regulated by a carburettor. In both departments things were found that could, and did, wear or go out of adjustment.  

The contact-breaker points relied on a rotating cam pushing on a nylon-type rubbing block to bump “the points” open. The block would inevitably wear, causing the spark timing to drift away from the correct setting. Furthermore, there was a constant tendency for sparking to occur between the points when they opened to interrupt the current through the coil.  

Sparking would lead to pitting, which damaged the finely machined faces of the points, thus lowering the current and weakening the voltage surge to the spark plugs. To prevent this, a capacitor (“condensor”) was fitted across the points, which worked after a fashion until it started to pack up.   

Understandably, the first task in a tune-up was usually to inspect the contact breaker points. Some workshops simply fitted a new set of points, willy-nilly. Then the adjustable gap between the points, when fully open, should be set to specifications and a dab of high melting point grease put on the rubbing block. The final step in the ignition department was to set the spark timing with the aid of a timing light. All this could be done by a seasoned mechanic in distressed overalls in half an hour.  

Moving on to the carburettor, a whole new can of worms opened. The choke action, the float level, the jets (main and auxiliary), the air correction screws, the butterfly spindles which leaked air, the accelerator pump. Here our seasoned mechanic might have to consult his mate, the resident carb guru. But within another half an hour the two of them should be ready to take the car for a test drive to the nearest fish-and-chips shop.  

That was your classic tune-up. It worked because the mechanics by and large understood what they were doing and the cars were designed to demand nothing more.  

All of that went out of the window when electronic engine management and fuel injection took over. Except for the air filter, none of the items attended to in the traditional tune-up could even be found on the new engines. A computer is now, effectively, performing an ongoing tune-up, and only a very foolhardy mechanic would tamper with its programmes. So, in our brave new world, how should owners approach the servicing of their cars?   

There is really only one way: with greater personal involvement. On many late-model cars the servicing schedule provides for major and minor services. Minor services mostly boil down to an oil change, inspection and top-ups of fluid reservoirs, inspection of the air filter, perhaps inspection of brake pads. All of this the average owner can do himself if he puts his mind to it. In fact, he can go one better and halve the recommended oil change interval for town driving. (Town driving should be regarded as severe conditions)  

This is the single most important thing an owner can do to extend the service life of an engine. Even if it is not practical to drain the oil yourself, you should buy the recommended oil, take it along to the workshop and stand by while the service is performed. If a workshop won't allow this, big red warning lights should switch on. An honest workshop has nothing to hide and should welcome personal involvement. Concern for your safety is sometimes used as an excuse. Offer to sign an indemnity, or better still, turn around, take your car and leave.  

When it comes to major services, acquaint yourself before with the full list of tasks to be performed. Some of them you will be able to do yourself. For the others, you would ideally want to take your car to a dealer's workshop. The problem is that the big workshops will probably not allow you to stand by while the work is done. For me, that is not negotiable, and I will then look around for a reputable, smaller dealer who will not object.   

I realise that standing in a cold, noisy workshop while your car is being serviced is not everybody's cup of tea. The next best option is to find a competent, well-equipped, scrupulously honest repairman to perform the services. They exist out there. But so do a multitude of imposters. Ask around, suss them out, be very wary.

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