A customer in the garden with an RAC Mobile Mechanic in the background.A close-up of a customer tending to her garden with an RAC Mobile Mechanic in the background.
Service, Repairs & MOT

Car diagnostic in Chelmsford

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

  • State of the art equipment
  • No hidden costs
  • Mechanics you can trust

£148.46

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

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 Chelmsford

We’ll come to you at home or work

RAC Mobile Mechanic in Chelmsford

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.

A customer tending to her garage with an RAC Mobile Mechanic in the background

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.

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 Chelmsford

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

BB Motors Solution Ltd T/A Platinum Motor Solutions

4.8/5

Established in 2008 with over 7 years of experience, Platinum Motors is a well-known, locally run business based in Romford. We pride ourselves on providing an honest and reliable service throughout the local area. At Platinum Motoring Solutions we are a small team of qualified and experienced mechanics offering a complete range of garage services. We undertake all car servicing and provide quality MOT testing and repairs as well as computer Diagnostics for all make and models As testament to the high standard of service and workmanship that we provide, we maintain many repeat customers and are highly recommended across the local Romford and Gidea park area. Want to find out if we can help you? Are you looking for a free estimate? Please feel free to contact us today.
376-392, Brentwood Road, Romford, RM25TD

A&R Motors Engineering Ltd

4.7/5

A&R Motors, Canvey's favourite workshop for full car servicing, brakes & clutch, suspension, engine repairs & tuning, exhaust fitting, welding and classic car restoration. Family owned and established for 35 years, we are possibly the longest running workshop in Canvey Island. We are not part of any franchise or chain, just a local garage with honest mechanics you can trust. Your safety is our key objective and our value for money service ensures you hassle free motoring at an affordable cost. We offer a full range of great value services for all types of car and van from personal vehicles to commercial fleets. We also cater for classic vehicles with vast experience in classic Volkswagen, Audi, Porsche and most American Cars.
11 Kings Close, Charfleet Industrial Estate, Canvey Island, SS80QZ

Eastern Garage

4.7/5

Eastern Garage is your local independent garage that has been established since 1950. We have been serving the local community for over 60 years and hope to do so for many more years to come. The current owner, Martin Sheath, took over in 1989 and runs a team of 10 employees. Our technicians have over 60 years of combined experience with all makes and models of vehicles. By choosing us to repair your vehicle, you can be assured that your vehicle will receive the care and attention it needs and deserves. We are able to carry out all repairs in line with manufacturers recommendations.
Wethersfield Road, Essex, CM7 4NT

Inverness Garage

4.3/5

We are a family run business in its second generation. Inverness Garage opened in 1970 and are a large independent garage operating in the centre of town, close to bus routes and train stations located near Southend and Leigh on Sea. We have been AA garage of the year (south east) three times. We pride ourselves on being an honest, friendly and very professional garage. We offer a full spectrum of garage services in Westcliff on Sea, from MOT’s and Servicing to the latest electronic diagnostics, car air conditioning services and good old-fashioned welding. There is little we can't do in-house, our expert technicians deliver exceptional customer service and expertise with an extensive network of specialised service partners we provide a one stop for all your motoring needs, all work carried out will be covered by our comprehensive warranty here at Inverness Garage in Westcliff on Sea. Should you require it we offer collection and delivery services as well as two loan cars should you need one whilst your vehicle is with us. If you prefer to wait while we work on your vehicle we have a comfortable waiting room for you to use. So sit back and rest assured your vehicle will be in expert hands at Inverness Garage.
Inverness Avenue, Westcliff-On-Sea, SS09DY

Harris and box vehicle solutions ltd

3.7/5

Harris and Box Vehicle Solutions Ltd is an independent workshop based in Witham. We provide the highest level of service across our expertise and never hesitate to go the extra mile for the satisfaction of our clients. Whether it is a major issue or a minor inconvenience, we will make sure that your car is ready to set off as soon as possible. We cover Witham and the surrounding Essex, Suffolk and Hertfordshire areas. We possess over 25 years of experience in the motor industry, working at main dealers and fast fits. We are also AA approved. Our professional mechanics can solve any issue that you are experiencing with your car with excellent workmanship and care. We never include any unnecessary repairs or hidden extras. So, when your car needs any repairs or periodic maintenance, you can rest assured that it is in safe hands with Harris and Box Vehicle Solutions Ltd.
36, Witham, CM83TH

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.