A little knowledge is a worry.

I know, I know, you don't have to tell me. The commonly quoted proverb is that a little knowledge is a dangerous thing - and it is, or can be. It can also be a worry.

Years and years ago, a neighbour and I went to evening classes to learn motor mechanics. This was back in the days when one went to night school not only to study for professional exams and qualifications (I did it for years before I managed to pass my banking exams and become an Associate Member of the Institute of Bankers or AIB) but also for cultural study such as conversational French, cookery or chess for beginners. Alan, for that was my neighbour's name, and I had become disenchanted with the prices charged by garages for servicing our cars and reckoned we could save money by doing the work ourselves. We became adept at changing brake pads, bleeding and adjusting brakes, adjusting tappets, dismantling carburretors and distributors - indeed, everything in the standard service and a bit more besides.

Nowadays it's a different story. For a start, I'm a lot less keen on standing in a cold wind on the drive fiddling around under the bonnet. In any case, it seemed a lot easier when there were two of us doing the job and Alan moved away years back. Anyway, with modern cars it's about all I can do to open the bonnet to check the oil and water. With my present car even changing a light bulb is a garage job. But despite this, I still read the question and answer column in the motoring supplement that comes with the Saturday edition of my daily paper. The questions asked cover a very wide range of motoring subjects and it is through reading these and, especially, the answers that I have learned what happens if a timing belt snaps and that there are such things as a dual mass flywheel, this latter being something that, apparently, can disintegrate without warning and do a great deal of expensive damage.

I had it at the back of my mind that later this year I should consider having the timing belt and associated pulleys etc changed in my car. I had the job done on my previous car - same make and model as this one - and it cost an arm and a leg. I also know that later this year I will have to spend quite a lot on a major service. With the worry of the dual mass flywheel at the back of my mind, I was thinking that maybe I should change the car for one that has a timing chain (doesn't need replacing) and does not have a dual mass flywheel (I don't actually know if mine does or not). That would also save the cost of the service and (maybe) a set of four tyres.

You see? Just enough knowledge to make life a worry.