When an engine starts to use oil, and the car is too slow to escape its own smoke-screen, the average motorist's thoughts naturally turn to an overhaul. But is it always necessary? Many engines are overhauled too soon, because the real reason for the oil consumption has not been established. It may be something as simple as a sump that has been over-filled, or else a leak somewhere, and it stands to reason that you should make absolutely certain the engine needs an overhaul, even if you have to get a second opinion.

On many overhead-cam engines the oil stem valve seals seem to wear out before anything else, causing the engine to smoke when opening the throttle after it has been closed for some time, for example when coasting downhill and then accelerating again.

There are various ways to acquire a reconditioned engine, so let's look at the options in order of preference:

1. The best sources are the engine- exchange services run by most of the major automotive manufacturing companies, but this is also the most expensive option. However, the advantage is that reconditioned units have to pass the same tests as new engines, and 12-month warranties are becoming the norm.

2. A less expensive source of reconditioned engines could be one of the numerous engine overhaul specialists, but the warranties and quality of workmanship vary from good to very poor.

3. Low-mileage engines are being imported, especially from Japan,
but they have to be treated with suspicion because such engines are seldom built to our local specifications and fuel quality.

4. Low-mileage engines from a scrapyard are often a good buy, because the engine will be complete, whereas most reconditioned units only include the block, pistons, crankshaft and con-rods, and sometimes the cylinder head.

5. If you know a trustworthy mechanic or garage, ask their advice. Some garages still overhaul engines to a high standard, and the advantage is that you can tailor the amount of work to be done, and expense, to your situation.

6. The worst thing you can do is to go to a garage that is not known to you, and ask them to overhaul your engine or supply a reconditioned unit. The chances of getting ripped off are extremely high. Many modern engines require far more expertise to overhaul than the engines of yesteryear, so the job should be entrusted to an expert.