Book a Car Diagnostic in Plymouth

Trustpilot rating for all RAC Mobile Mechanics.

Why choose the RAC for a car diagnostic?

With RAC Mobile Mechanics, you can avoid the hassle of taking your vehicle to a garage. They can do a vehicle diagnostic check on your driveway, so you don't even need to leave the house.

When it comes to diagnosing issues with your vehicle, our friendly expert mechanics are here to help. We use state-of-the-art diagnostic equipment to accurately identify any problems, ensuring your vehicle runs smoothly and safely. The price includes the diagnostic service – no hidden costs. Just friendly, honest experts.

Whether you're near Plympton, Plymstock, Crownhill or Derriford in Plymouth, RAC Mobile Mechanics offer a flexible way to get a diagnostic at home, with simple, transparent pricing.

Close up of an RAC Mobile Mechanic underneath a car

Our top pick in Plymouth

We’ll come to you at home or work

RAC Mobile Mechanic in Plymouth

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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.

Close up of an RAC Mobile Mechanic running a vehicle diagnostic check

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.

OEM quality parts

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.

Mechanics you can trust

Our mobile mechanics are friendly, honest, and backed by the RAC.

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:

Clutch Replacement

We diagnose and repair clutch issues – whether your clutch is heavy or slipping, or you’re having trouble changing gears.

Alternator repair

We check and correct alternator faults to keep your charging system running smoothly.

Oil change

Oil is vital to a healthy engine, so it’s important to change it regularly.

Brake pads & Discs

If your brakes are making noise or you’re noticing reduced stopping power, it’s likely time to replace your brake pads or discs.

Average cost of a vehicle diagnostic by car make^

The RAC charges a flat rate for the cost of a car diagnostic but prices may change due to inflation. According to RAC data, the average cost of a car diagnostic is £87.

Make	Average price
Ford	£105
Vauxhall	£105
Volkswagen	£105
Peugeot	£104
Mercedes-Benz	£104
Nissan	£106
BMW	£107
Audi	£106
Renault	£104
Citroen	£104

^Average price quoted for RAC Mobile Mechanics from 01/01/25 to 31/03/25.

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

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.

A close up of an RAC mobile mechanic looking under the hood of a car

Try one of our RAC Approved Garages

View all garages

Zn motor repairs

4.8/5

We are a family run business located on the outskirts of Tavistock in West Devon. Our team of Technicians are equipped to deal with any issues that may arise from a mechanical failure. We have the latest Diagnostic equipment and Specialist tools to undertake those jobs that may have otherwise needed to go to the Main Dealer. We are also able to cater for LCV and HGV repairs. All general mechanical work undertaken at reasonable rates.

Unit 6, Pitts Cleave Ind Est, Tavistock, PL190PW

Polyne Garage.

4.4/5

Here at Polyne Garage we are a small local, independent, family run business and have been serving Saltash, Liskeard and the surrounding area for over 60 years. We offer a genuinely friendly and personal service and as a Unipart Car Care Centre, as well as first class mechanics and workshops, we offer top quality parts at competitive prices. We provide a unique 12 month / 12,000 mile warranty on parts and labour, which is honoured at over 2000 Car Care Centres nationwide. We also understand that dropping off and collecting your vehicle is not always convenient so we offer a collection and delivery service, please feel free to contact us for more information on this. We can estimate all jobs and will advise you in advance if any variation is necessary. Our opening hours are Monday to Friday 8:00AM - 5:00PM. From all of us here at Polyne Garage we look forward to hearing from you.

Trerulefoot, Saltash, Cornwall, PL125DA

Marshall Motors SW Ltd

4.0/5

Marshall Motors SW LTD is an independently run business that prides itself on offering unrivaled sales, services, MOTs and mechanical repairs to its customers in the local area and further afield.We offer a comprehensive range of services so whether you need to book an MOT, have your car inspected for its annual check over, or if you have an urgent problem that needs attention, our team of highly specialised mechanics are on hand to fulfill your requirements. RAC ApprovedRMI ApprovedTrust My Garage ApprovedMotor Codes ApprovedTrading Standards Approved

26 Valley Road, Plymouth, PL71RF

Newnham Park Garage

We 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.

7 Kay Close, Plympton, Plymouth, PL74LU

Car Check Plymouth Limited

Based in Plymouth - we are a family run, independent garage. Our business has grown steadily over the years by providing a reliable, professional, and trusted service. We understand that customer service is key to our success and whilst we are delighted to welcome new customers, we greatly value the continued support of our existing customers. We have 6000 square feet of fully equipped workshops, including 5 service ramps. In addition to our general servicing and repair work our technicians are also trained and competent in: Air condition servicing and Exhaust replacement. Use our many years of experience to maintain and repair your vehicle to the very highest standards. We like to get the job done at the best price for you.

Units 11 12 14 Broxton Drive Pomphlett Farm Ind Estate, Plymouth, PL97BG

Frequently asked questions on car diagnostics

How much does it cost to diagnose a car problem?

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.

Is a car diagnostic test worth it?

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.

Can I do a car diagnostic myself?

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.

How long does a car diagnostic test take?

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

What are common car diagnostic codes?

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.

Is a car diagnostic test necessary for a service?

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.