Whether it’s in the house, garden or car, there are certain things that are best left to the experts. Here we look at parts of the car and jobs that might seem like a good idea at the time but are best not attempted – without specialist knowledge, tools and experience.
Make a Horlicks of some apparently straightforward tasks and it’ll cost you a fortune. Hear that timing belt you carefully replaced fail because you didn’t do it properly and it could mean a new engine. Fit replacement suspension parts incorrectly and it’s not just you who could suffer; there are far wider safely implications. Read on to see more jobs that are best avoided.
Jet wash or steam clean the engine
You might think of your car’s engine as being functional but in fact it’s a work of art. And you wouldn’t set about cleaning up one of Van Gogh’s finest with a dirty rag and some white spirit. Jet washing an engine is the automotive equivalent of a blunt instrument.
Although the mechanical parts of an engine are fairly robust and tolerant to moisture, the electrics aren’t. And modern cars have a lot of electrics. Steam cleaning is less damaging than jet washing. But you’re still introducing moisture to delicate electronic parts such as ignition coils and spark plugs.
Steam cleaning an engine will smarten your car up if you want to impress your friends or a potential buyer. And it’ll mean you don’t get covered in oil if you ever have to venture under the bonnet. Just leave it to the experts.
Mess with the Airbags
The instant sensors detect a massive deceleration, a switch is flicked to combine potassium nitrate with sodium azide. The result fills the thin nylon airbag with nitrogen. All this happens in a fraction of a second so it’s fair to say that fiddling with the contents is akin to messing about with an unexploded bomb. Just don’t.
Interfere with the ECU
Would you open your home computer and mess about with the delicate printed circuitry inside? Thought not. The Electronic Control Unit is your car’s brain. It oversees all its electronic functions and that means pretty much everything a car does from starting the engine to deciding how much fuel it consumes.
Mucking up the ECU can be an expensive business. A replacement might cost anywhere between £100 and £1000 by the time it’s been fitted and set up. Go to a franchise dealer and it’s likely to cost even more.
There are specialist companies that deal with what’s known as chipping. This is remapping the ECU programme to improve performance, whether that’s for better bhp or more mpg. It’s best to leave them to it. And if you use one of these companies, make sure they’re reputable and their work comes with a guarantee.
Electric and hybrid cars
More alternative fuel vehicles than ever are being sold in the UK. There are now thousands in circulation and they’re not like normal cars. The Institute of the Motor Industry (IMI) has already issued a warning that unqualified mechanics are at risk of electrocuting themselves on these motors.
The reason is that some of the circuits on electric cars run at more than three times the 230v mains supply used in our houses. Hardly surprising when you consider that getting a 1.5-tonne car to 70mph takes quite a lot more current than powering the average domestic fridge.
IMI chief exec Steve Nash said that mechanics need proper training before dealing with such cars. He warned: “Sooner or later somebody is going to attempt to do something they shouldn’t do and they are going to fry themselves. That will either be the person working on it who gets a 600 or 700-volt shock or it might be a member of the public exposed to a fire risk. This isn’t scaremongering. It’s real.” DIY mechanics take note.
James is an award-winning motoring journalist with more than 20 years’ experience on national publications. He writes a popular consumer column for the Daily Telegraph Motoring section and contributes features to MSN Cars. James was motoring editor for the News of the World for seven years and has held senior editorial staff roles on Auto Express, Autosport and AutoClassic magazines.