Book a Car Diagnostic in Chelmsford

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

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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 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

View all garages

City Electric Vehicle Engineering

High level vehicle diagnostics (electrical & mechanical) with 10 years worth of extensive Hybrid / electric vehicle experience - whether its a normal petrol, diesel vehicle or a modern day electric / hybrid vehicle we can solve most issues that other garages can't.

Unit 15 Oyster Place, Montrose Road, Chelmsford, CM26TX

Saltmarsh Automotive LTD

BMW/Mini/German car specialists, repairs offered on all makes and models. IMI & EV qualified Free collection & delivery offered to all customers in the local area, please call to check collection is offered for you however our radius if from Bradwell-On-Sea to Southend then up to Kelvedon area

Unit L The Mayflower, Mill Road, Mayland, CM36EQ

Wickford Autocentre

Going by first impressions, Russel Gardens in Wickford may not be the sort of place where you would expect to find a modern auto centre, and especially not one that can offer you fixed MOT and Servicing prices. However, that is exactly what you get with Wickford Autocentre. When Mr Choudhury decided to purchase the site of a former garage and used car sales dealer, he decided it would be to start afresh by completely stripping the site of its infrastructure including tools and machinery. Following a very high figure cash injection into this business, Wickford Autocentre now offers many facilities and services, many of which are usually only found in main dealerships. These include but are not limited to; MOTs / Servicing / Tyres / Nitrogen Tyre Inflation / Brakes / Auto diagnostics / Air condition servicing / Timing belts / Head gasket / All major repairs undertaken / Accident management services. Economical servicing options for are available every pocket and we also offer up to 12months parts and labour warranties to ensure total customer confidence. Every service includes free brake, exhaust, shocks, tyre, battery and clutch checks. A top-down overhaul has catapulted the auto centre into popularity with the local vehicle operators and motor traders. With a transparent, competitive and fair pricing strategy, a significant number of private car users are making a switch to Wickford Autocentre. So if you are looking for a customer friendly, economical and competent technical team to look after your vehicle, call into Wickford Autocentre today!

Russell Gardens, Wickford, SS11 8BH

LDN AUTO SERVICES LTD

Welcome to LDN Auto Services, we take pride in offering a wide range of services to cater to all your vehicle repair needs. From basic maintenance tasks such as oil changes and brake inspections to more complex repairs like engine overhauls and transmission replacements, our team of skilled technicians is here to ensure that your vehicle is running smoothly and efficiently. Trust LDN Auto Services for all your automotive needsHighly experienced technicians with expertise in a wide range of vehicles - RAC Approved Garage - State-of-the-art equipment to diagnose and repair vehicle issues efficiently - Competitive pricing and transparent billing for quality service

Unit 9, Harrison Drive, Braintree, CM71DE

L V GROUP MOT AND SERVICE CENTRE LTD

L V GROUP MOT AND SERVICE CENTRE LTD MOTS TYRES BRAKES DIAGNOSTICS SERVICING ENGINE REBUILDS BODY SHOP AIR CON

Unit 4 Newlands End, Basildon, Essex, SS156DU

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.