Car Servicing & Repair
Frequently asked questions (faqs)
This is a summary of our answers to the most common questions asked about car servicing and repair.
» Why don't you get a full workshop manual when you buy a new car?
» Why isn't clutch failure covered by the warranty?
» Can you give details of the service schedule for my car?
» Do I have to get my car serviced by a main dealer?
» Who can help fix problems with an automatic gearbox?
» My handbook says the airbag should be renewed after 10 years. What should I do?
» Where can I buy a good reconditioned engine?
» What's a reasonable labour rate for garage repairs?
» What does it mean when a garage adds an environmental charge to my bill?
» When should the cambelt be renewed?
» Can I get the manufacturer to pay for cambelt failure two months after the end of the warranty?
» How long should a catalytic converter last?
» Is it really necessary to get air conditioning serviced?
» What are the advantages of synthetic and semi-synthetic oils?
» How much less is my car worth following accident damage and repair?
Why don't you get a full workshop manual?
There are many reasons why it is not practicable for car manufacturers to supply detailed technical information and manuals with all new cars;
- The vast majority of car owners have no interest in car maintenance beyond fluids checks and tyres - bundling full technical manuals would add to cost.
- Modern cars are much more complex than those of 10 or 20 years ago and there is much less scope for DIY now. There are serious health & safety concerns too.
- With electronic control and widespread adoption of multiplexing most fault diagnosis and repair requires use of dedicated offboard diagnostic equipment.
- It would be very difficult to provide manuals and wiring diagram. Information in handbooks is fairly generic, but more and more technical material is vehicle specific - down to particular VINs and a lot is just programmed directly into the diagnostic machines.
- Information is available from dealers or from manufacturers' website, but individual customers would pay the same rate as a dealer or independent garage. A diagnostic machine would be required to make sense of it though.
- Electronic information in this format allows manufacturers to make improvements and adjustments. Issued workshop manuals wouldn't allow this.
It's right of course that dealers don't have a monopoly on repairing their products. This is why we and other motoring clubs across Europe have championed changes in legislation to ensure that independent garages get fair access to the same technical information as the franchise dealers.
It's also the case that during the warranty period manufacturers can no longer insist that service and repair is carried out by their own dealers. Together these measures are aimed at maintaining a level of competition in car servicing.
Why isn't clutch failure covered by the warranty?
The clutch unit can suffer premature wear as a consequence of poor driving style. Wear can be hastened by the driver resting a foot on the pedal (riding the clutch), 'holding' the car on the clutch on hills rather than using the handbrake or letting the clutch slip excessively. If the garage has repaired the car, but say the failure has been caused by driver abuse, then ask them for the old components and seek a second opinion - possibly from another garage or mechanic.
The garage is entitled to ask you to pay for the work before allowing you to take your car. If one of the components has broken and caused the failure, then you may be able to claim under the warranty. Regrettably, if there is no evidence of manufacturing or material defect, you will have to pay for the new clutch and cost of fitting.
Can you detail the service schedule for my car?
We're unable to provide detailed extracts from manufacturers' workshop manuals.
The vehicle handbook should include basic service interval information.
Any reputable independent garage should have access to manufacturer's technical data, including details of the manufacturer's service times, schedules and operations.
AA Members can get discounts on servicing, repairs and MOTs with Nationwide Autocentres. See the AA Members Club for more details.
Do I have to get my car serviced by a main dealer?
The European regulations governing the sale and after-sales servicing of new cars changed in October 2003. For new cars purchased after that date you are no longer obliged during the warranty period to get the car serviced by a franchise dealer.
You must however continue to get the car serviced according to the manufacturer's recommended schedule and criteria using only manufacturer approved parts.
The legislation only applies to the part of the warranty offered by the manufacturer, i.e. insurance-backed extended warranties offered by dealers are not covered.
If you do have the car serviced outside the dealer network it is essential that it's done to the maker's recommended schedule and criteria using approved parts. You must also keep records to enable you to demonstrate to the manufacturer that servicing was undertaken to their requirements.
Warranty work should still be undertaken by the franchised dealer as it is easier for them to deal directly with the manufacturer.
There's more information in the consumer advice section of the Society of Motor Manufacturers and Traders (SMMT) website, www.smmt.co.uk.
Who can fix problems with an automatic gearbox?
Automatic gearboxes are complex pieces of equipment and sometimes need very specialised knowledge.
If it's a problem with the electronics which control the gearbox, it is better to seek an opinion from a garage which deals in your make of car as they receive regular software updates from the manufacturer. This may cure the problem.
If it's thought to be a problem with the gearbox itself, then you may achieve more success if you contact a member of the Federation of Automatic Transmission Engineers.
Airbag renewal after 10 years. What should I do?
Cars which are now coming up to the 10 year airbag renewal point were the first to be fitted with a new system in which manufacturers lacked long term knowledge and confidence. There was an agreement between car manufacturers and manufacturers of airbag systems that they would validate (or test) them for a 10 year life span.
A sodium azide tablet produces the gas which inflates the airbag, and this tablet and the explosive device are sealed. Although some moisture ingress is possible it should not affect performance. There will also be some natural chemical decay, but again this shouldn't stop the airbag from working.
Some manufacturers are more concerned that the airbag cover could become brittle through aging and a flying fragment cause eye damage. The same manufacturer combinations have more recently increased the validation period to 15 years on later cars without making any major changes to the system.
The MOT test doesn't take airbags into account as they are not specifically required by legislation.
Where can I buy a good reconditioned engine?
The word 'reconditioned' has different meanings to different repairers. Some may do little more than apply a fresh coat of paint, while others will dismantle the engine fully, machine bearing surfaces and rebuild the engine to a good standard using many new parts.
Don't be tempted by cheap units from back street garages. Previous history and internal condition are often unknown and they can work out to be more expensive in the long run. Resolving problems can be very difficult, too.
We recommend that you buy a reconditioned/remanufactured engine from a company which is a member of the Federation of Engine Remanufacturers (FER). These engines have to be rebuilt to a high standard and if there are any problems you can seek help/arbitration from the federation.
What's a reasonable garage labour rate?
Vehicles are now very complex with multiple sensors and electronic control units to keep exhaust emissions to a minimum, improve stability/braking and to operate sophisticated safety systems. Technicians at franchised garages need to be highly trained and must attend many manufacturers' training courses. Not only are the courses expensive, but the technicians demand salaries to match their skills.
Garage hourly rates vary considerably according to location, the nature of the facilities and whether or not they hold a franchise. A BMW dealer in South London may charge around £180 per hour and another in Worcestershire, £111 per hour. Rates for Ford dealers range from around £64 to £96.
In contrast, independent garages are not under the same pressure from vehicle manufacturers to maintain prestigious premises with lots of customer facilities and, as a consequence, may be able to charge less than half the labour rate of their franchised counterparts. Before booking your car in for servicing we recommend that you phone several garages and compare their hourly labour rates.
What's an environmental charge?
Cars contain many toxic substances such as oil, antifreeze, brake fluid, batteries, etc, and each one of them must be disposed of correctly. This often involves temporary storage in approved bins.
Waste disposal specialists who have to maintain registered vehicles, premises and facilities appropriate for the materials being handled then collect the contents of the bins. The licences to carry out this type of work are expensive, and the garage itself incurs significant costs.
When should the cambelt be renewed?
There's not a standard change interval for cambelts.
Depending on the model and the manufacturer, the recommended interval can be anywhere between 30,000 miles and 100,000 miles. There will often be a time-based interval specified too e.g. 60,000 miles or five years, whichever is the sooner.
Check with a franchise dealer for the model concerned to establish the requirement for your particular car - make, model, engine number and model year.
Failure of the cambelt will in most cases result in serious damage to many other components in the engine - a replacement engine may well be required!
It does no harm to renew the belt early and you should do so if you buy a used car and are in any doubt if the cambelt has been renewed according to the maker's schedule.
Can I get the manufacturer to pay?
The manufacturer is under no obligation to help you once the warranty has expired, as it's generally accepted that faults caused by manufacturing or material defects will show up during the warranty.
Many will provide some financial help, but this won't cover all the repair costs and you must be able to meet certain conditions - the car must have been serviced in accordance with the manufacturer's recommendations using the correct parts and oils for example.
The repair should be done at a franchised dealer for your particular make of car. Ask the dealer to submit a claim to the manufacturer on your behalf. You could be required to pay for the repair first and some of the costs may then be refunded by the manufacturer.
Unexpected and expensive car repairs are upsetting, but it is essential that you remain calm and polite. You need to keep the garage and manufacturer on your side.
How long should a catalytic converter last?
It's not unusual for catalysts to last 10 years, though actual life depends on mileage and engine tune. 50,000 miles is perhaps a more reasonable benchmark, and most owners can expect to replace the catalytic converter once during the life of the vehicle.
If failure occurs early, it's important that the reason for failure is identified and the cause rectified before fitting a new CAT, otherwise the replacement can be expected to fail prematurely too.
There are three main failure modes
- Melt down - unburned fuel entering the catalyst ignites on contact and the extreme heat literally melts the ceramic matrix. Poor ignition timing, a faulty oxygen sensor, worn or defective spark plugs, incorrect fuel mixture and other ignition/fuel injection related faults could lead to this failure.
- Carbon deposits - oil or antifreeze entering the combustion chamber/exhaust system can lead to a build up of carbon on the matrix, which increases back pressure leading to overheating and poor performance.
- Catalyst fracture, - the ceramic matrix is fragile and can break-up as a result of excessive vibration or external impact. As the matrix breaks up back-pressure increases and overheating can result.
Must I get air conditioning serviced?
Regular servicing is important for health and to maintain the system working effectively, as up to 15% of the refrigerant gas will be lost annually from a nominally gas-tight system.
- Run your air conditioning at least once a week throughout the year.
- Have the refrigerant gas checked regularly and topped up to manufacturers' recommended levels.
- Help improve hygiene and air quality with a regular cabin filter change, as it can become blocked with pollen.
- A regular air duct clean helps remove the bacteria and fungi that can cause unpleasant odours.
- Service air-conditioning units every 30,000 miles or two years to avoid costly repairs.
What are the advantages of synthetic oils?
Synthetics and semi synthetics give improved performance at high temperatures and support extended drain intervals. They are generally the preferred choice for high perfomance cars or for motorists who particularly value long life/durability.
Your vehicle handbook should specify the grade/type of oil to be used based on the results of extensive durability / extreme environment testing by the manufacturer.
If synthetic oils are recommended then that is what you should use.
We don't recommended mixing mineral and synthetics, nor do we recommend switching to synthetic oils unless the vehicle handbook specifies that you may do so.
If the manufacturer has confirmed that synthetic oil is suitable for your vehicle and you intend to switch then you must make sure that the engine is drained fully of mineral oil first.
How much less is my car worth following repair?
The Brightmore versus Eaton case in the early 1980s set the precedent on this issue. This involved a fairly new Mercedes, and the judge decided the loss of value (also known as 'diminution in value') was worth 15% of the normal retail value of the car.
It's important to remember that the car involved in this case was a 'luxury' model, and more recently judges have reduced awards to nearer 11%.
If you intend to go to court on this issue, then be aware that judges are generally less sympathetic to claims of this nature. Older, run-of-the-mill cars will suffer a smaller diminution in value, and for commercial vehicles the loss is regarded as negligible.
For general legal advice we recommend that you contact your local Citizen's Advice Bureau.