Book a Car Diagnostic in Harrow

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.

Close up of an RAC Mobile Mechanic underneath a car

Our top pick in Harrow

We’ll come to you at home or work

RAC Mobile Mechanic in Harrow

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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 Harrow

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

AVS Ltd.

We are a well established local Harrow garage, providing a wide range of garage services including Servicing, MOT's, Bodywork Repairs, Tyres, Brakes and Clutches to name just a few. We cater for all makes and models of vehicles and use the latest equipment in our fully equipped workshop. Many services can be carried out while you wait or we can provide you with a courtesy car upon request.

109A Roxeth Green Avenue, Harrow, HA28AB

Kwik Fix Motors LTD

Our business has been established for over two decades and we proudly work in partnership with Madena Motors, based in South Harrow. We offer a one stop shop, delivering services BSB or B2C. We cover a wide range of services from MOTs class& 7 along with repairs to all brands of vehicles. Our staff are fully qualified operating to DVSA standards. We are also an AA and RAC approved garage. Please feel free to contact us for all you motoring needs.

2A Tudor Road, Harrow, HA35PE

The MOT Centre

Based in Hatch End, The MOT Centre has a team of expert mechanics on hand to deal with all your car repair requirments. Our repair service uses the most up to date tools and equipment to repair any make and model of car. We keep most a range of parts in stock, or parts can be delivered within the hour by one of our suppliers, so most work can be done while you wait. We can undertake insurance work and also offer sub-contracted work.

Cornwall Road, Hatch End, Piner, HA54LS

Car Care Centre - Wembley Ltd

Car Care Centre (Wembley) Ltd offers a trusted and efficient service to the local community, maintaining high standards in automotive care. Our team, led by the knowledgeable Dipesh, is dedicated to providing straightforward, honest, and professional automotive services. From minor repairs to major overhauls, each task is handled with precision and integrity. We believe in building lasting relationships with our clients, ensuring their vehicles receive the best care possible. Experience the difference at Car Care Centre, where exceptional service and customer satisfaction are at the forefront of our operations.

558 Market Way, Off Turton Road, Wembley, HA02BT

Yaash Motors.

Established in 1997, Yaash Motors trades is one of the leading car garages in Wembley serving trade and private customers throughout the north and west London areas. We provide a complete range of traditional services alongside professional body modifications primarily aimed at the popular Volkswagen Golf models. Yaash Motors specialises in the delivery of a professional, reliable service where fair, open and transparent pricing is a standard feature in all of our work. We have a comfortable customer waiting room where you can enjoy refreshments and WIFI. Our team strive to provide a fantastic customer experience and will always deliver you with honest and professional advice.

Unit 5A, 255 Water Road, Wembley, HA0 1JW

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.