Service, Repairs & MOT

Car diagnostic in Cardiff

Book an RAC Mobile Mechanic and we’ll come to you at home or work.

  • 12-months parts guarantee
  • Honest pricing
  • Exceptional customer service

£290.07

Average price for this repair in Cardiff in the last 30 days^

Trustpilot rating for all RAC Mobile Mechanics.

Why choose the RAC for a car diagnostic?

At the RAC, we've got over 125 years' experience helping UK drivers. We have the skills and knowledge to keep your vehicle running.

Plus, with RAC Mobile Mechanics, you can avoid the hassle of taking your vehicle to a garage when you need a repair. We’ll come to you, at your home or work.

Close up of an RAC Mobile Mechanic underneath a car

Our top pick in Cardiff

Our top pick

RAC Mobile Mechanic in Cardiff

At the RAC, we’ve got over 125 years’ experience in offering complete peace of mind to our members. We’re best known for our breakdown service. And now – our new RAC Mobile Mechanics are here to help make every day motoring easier. If you need a service or repair, they’ll come to you at your home or work.

Book a car diagnostic

Our mobile mechanics will spend up to 30 minutes checking your car for faults and talk you through any repairs you might need and give you a report for your records. There are various ways we can check for faults, which could include plugging in to check your car’s onboard engine management system.

We use original equipment manufacturer (OEM) standard parts, which means every new part will be the same standard and same quality as the original part it replaced.
Our mobile mechanics are friendly, honest, and backed by the RAC.
Close up of an RAC Mobile Mechanic running a vehicle diagnostic check

Book a repair

It’s easy to book a car repair online. We bring the garage to you with RAC Mobile Mechanics, or find a trusted local garage. Common repair jobs include:

We diagnose and repair clutch issues – whether your clutch is heavy or slipping, or you’re having trouble changing gears.
We check and correct alternator faults to keep your charging system running smoothly.
Oil is vital to a healthy engine, so it’s important to change it regularly.
If your brakes are making noise or you’re noticing reduced stopping power, it’s likely time to replace your brake pads or discs.

And it’s not just car diagnostics that we do in Cardiff

Mobile mechanics bring the garage to you, saving you the hassle of getting your car to a garage. If you need a service or repair, they’ll come to you at your home or work.

Try one of our RAC Approved Garages

Cardiff Auto Electrics

4.7/5

Cardiff Auto Electrics is your new destination for all car and vehicle diagnostics in Cardiff and South Wales. Our specialist team have decades of experience with most makes and models of cars available, and have diagnosed thousands of faults on a huge range of vehicles. From engine management lights, to transmission and steering faults, our equipment covers all auto electrics and diagnostics and can help you find the issue to your problem efficiently and quickly. We cover most makes and models past and present regardless of age, so contact us to book your diagnostic and auto electrics appointment today.
281 Penarth Road, Cardiff, CF118YZ

IN'n'OUT Autocentres Cardiff

4.3/5

At IN’n’OUT Autocentres we offer fixed prices MOTs and Servicing for any make and model of car with no hidden extras. We are proud to be a ‘Which? Trusted Trader’ so we are really a garage you can trust. We also have a 5 Star Trustpilot reviews rating. We provide OEM parts and 12 months warranty on all parts and servicing. We only use premium Castrol oils in all servicing. Our services are all completed ‘while-u-wait’ so you have never have the inconvenience of losing your car for the day. You can watch your car as it is being worked on through the viewing window or sit back and relax in our clean and comfortable customer lounges with FREE Wi-Fi and coffee and read the latest magazines. Check out our latest reviews and BOOK NOW!!
In'n'out Cardiff, Culverhouse Cross, Cardiff, CF5 5TG

Promotive BMW MINI

4.0/5

Promotive is one of the largest independent BMW and MINI specialists in the country. Our technicians are both BMW specialists & MINI specialists trained and have the most up-to-date diagnostic equipment to pinpoint any faults in your car as quickly and accurately as possible. Any parts that need to be replaced will be of the same quality as those that were originally fitted on your vehicle. We work to a code of practice. This commitment to customer care gives you peace of mind in knowing that you are going to be given not only the best technical service, but also the best customer service. Promotive is run by John O’Sullivan who has 30 years BMW knowledge and training.
66 Tregwilym Road, Rogerstone, Newport, NP109EJ

Cardiff MOT Centre

3.3/5

Are you looking for a friendly, family-run independent garage dedicated to the drivers of Cardiff, then you’ve come to the right place. We have over forty years’ experience in the motoring industry and are committed to delivering quality repair work at the most affordable prices. We are proud to offer a wide range of dealership-standard services at much more affordable prices. So, if your vehicle needs an MOT test or service, a diagnostic test, tyre repairs or replacements, brake inspections or a general repair, book an appointment with Cardiff MOT & Service Centre today.
13 Ipswich Road, Cardiff, CF239AQ

John Dolbear Tyre & Auto Services Ltd

3.1/5

John Dolbear Tyre and Auto Services are an established local independent garage and are proud to be members of Autofirst Network – a nationwide network of independent garages operating to the Network’s 6 core values of Capability, Consistency, Care, Clarity, Cost Effectiveness and Customer Focus. For your added peace of mind we are members of the Motor Ombudsman service which is approved by The Trading Standards Institute. In short, we are a local garage you can trust offering you the support and service guarantees of a national network, giving you complete peace of mind.
North Road, Cardiff, CF14 3AF

Frequently asked questions on car diagnostics

The cost you pay can vary depending on the type of car and how complicated the diagnostic test. Check with your mechanic for a quote.

Yes, a diagnostic test may save you a lot of money. It finds issues early before they become costly repairs. It can also keep your vehicle running efficiently and safely.

While you can buy a diagnostic tool, interpreting the results needs expertise. It’s best if you to have a professional mechanic perform the test.

Diagnostic tests take from 30 minutes to a few hours. This depends on what issues are being looked at.

Common diagnostic trouble codes include:

  • P0300: Random/Multiple Cylinder Misfire Detected
  • P0420: Catalyst System Efficiency Below Threshold
  • P0171: System Too Lean (Bank 1)

These are general examples, so your car may have different codes. Always check with a mechanic so you get an accurate diagnosis.

Yes, they are. Regular diagnostics can help keep your car in good health. It makes sure that underlying issues are addressed quickly, so you can drive with peace of mind on the road.

Again, keep in mind that mechanics might have their own checklists. Chat with your mechanic to be sure that they address any specific issues you have.