The inquiry announced yesterday has been set up after surveys by trading standards departments uncovered an alarming level of shoddy workmanship and bad practice in garages. The OFT said that complaints to local authorities had doubled over the past decade, to 27,000 a year.
Officials are considering sending unmarked test vehicles - complete with glaring faults - to garages as part of their inquiry. They also plan a survey to find out whether women get a worse deal. John Bridgeman, the OFT's director-general, said: "We all trust garages enormously with these incredibly complex pieces of machinery. The question is whether that trust is justified.
"We are not suggesting that the sector is rife with rogue traders, although we know that rogue traders do exist."
Mr Bridgeman said the OFT would pay close attention to bigger garages to find out whether they are more trustworthy than smaller traders. "If the big companies are being careless and the smaller ones being careful, I want them to get the business. I'm very interested in the feeling that if a consumer goes to a big garage rather than a small operator they will get a better job done - that might be a myth."
A survey by trading standards officers in Birmingham two years ago found that only one garage out of 22 carried out a complete service on an undercover test car. Surveys exposing bad garages have also been conducted by trading standards departments in Liverpool, and in Lewisham and Southwark in London.
Mr Bridgeman said research by local authorities had found that little or no information was given to customers about the work that had been done. He added: "Far more worrying is the fact that they also found evidence that known faults were not corrected, faults were introduced during the service, or work was so shoddy that it posed a threat to road safety."
The car repair and servicing market is worth nearly pounds 9bn a year. Britain has more than 26 million cars and on average about pounds 300 a year is spent on each vehicle.
The OFT said the inquiry should be completed early next year. An inquiry into the used car market by the OFT was published in 1997. It found eight million used cars were sold each year and that one buyer in six had a problem with the purchase within six months.
Last month the OFT referred an investigation of car manufacturers and their relationship with dealers to the Monopolies and Mergers Commission, now the Competition Commission.
The Consumers' Association called for tough action by the OFT. Andrew McIlwraith, motoring editor of Which?, said: "We have been monitoring this issue for many years and have found it to be a serious ongoing problem for car owners. The OFT investigation must go beyond a simple assessment of the size of the problem.
"The OFT must put forward concrete proposals and the Government must take swift and decisive action to resolve this serious and widespread problem for car owners."Reuse content