Car Diagnostics | Book a Car Diagnostic for your Porsche

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 for your Porsche

We’ll come to you at home or work

RAC Mobile Mechanic for your Porsche

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

For a limited time, get £50 off repairs over £150 when you book a diagnostic test. Offer ends 09/12/25, 09:00.^**
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.

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.

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:

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.

And it’s not just car diagnostics that we do for your Porsche

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

Swanmore Car Repair Centre

4.8/5

Swanmore Car Repair Centre is an independent repair garage established in 2008. We offer a wide range of services and commend ourselves by providing the best quality and efficiency on every single job we undertake. Our clean, modern and well-equipt premises allow us to welcome any repair and rectify it. We cover anything from a simple service, right through to a full engine rebuild. On-site we have a vast range of different diagnostics equipment from a range of leading suppliers. We can facilitate diagnostics to complete vehicle reprogramming depending on individual need. We can accommodate all vehicle make's and models and are happy to be able to provide you with a reputable dealer level of service, all for the price of an independent garage. Our team specialise in Clutch, Cambelt and Brake repairs and are proud to be rated a national top performer. We are members of the approved garage network This ensures you have peace of mind and confidence when repairing with us. All of our team here at Swanmore Car Repair Centre are fully qualified and trained to the highest standard. We strive in making sure we deliver professional work with results, always put the customer's needs first. Customer satisfaction is essential on each and every job, no matter how big or small. We are very pleased to be able to provide both a collection and delivery service within 10 miles, or a courtesy car subject to availability. Of course, however, you may just prefer to wait in our comfortable waiting room, with free Wi-Fi and refreshments on offer.

Unit 7 Swanmore Business Centre, Lower Chase Road, Swanmore, Southampton, SO32 2PB

Kncustoms LTD

4.1/5

Kncustoms LTD are based in Sheffield offering the best possible service to all our customers from the more basic servicing to the extreme - an engine change. We pride ourselves in offering the best customer satisfactory, and going the extra mile!

Unit 1 And 2 Acers Hill Lane, Acers Hill Lane, Sheffield, S94TY

Ian Bright Motor Engineer

4.7/5

Ian Bright Motor Engineers is a friendly independent garage situated in a beautiful countryside location in Halnaker, Chichester. Established since 2013, our small team are dedicated to delivering you the highest levels of customer service. Our workshop is fully equipped and we cater for all makes and models of vehicles, offering our customers a comprehensive range of repairs, maintenance work, servicing and MOT’s. Owner Ian has over 47 years of experience, having started his 5 year City & Guilds apprenticeship back in the 70’s. City and Guilds qualifications are a lot more intense and labour intensive compared to the more modern qualifications available to mechanics nowadays, and we were taught how to fix and repair parts as opposed to simply replacing them, which is standard practice in most places today. I have experience working with older classic cars, alongside newer more modern ones too, and no job is too big or too small for us to take on! Most of my customers have been with me for years and know that by choosing my company to undertake works on their pride and joy, they will receive fantastic workmanship alongside a personalised service. We would never advise you doing anything to your vehicle which was unnecessary as some garages do purely for profit, priding ourselves on our honest core values. My son, who was trained in-house alongside me, has branched out into classic and vintage race cars and is fast gaining a fantastic reputation for his first-class trimming, and my eldest grandson Lewis is now working with me and is undergoing his apprenticeship too. Three more grandsons are also looking to come on board and keep this garage running with a strong family presence.

Unit 2 The Workshops, Thicket Lane, Halnaker, PO180QS

Philip Lund Motor Engineers Ltd.

5.0/5

We specialise in car and motorcycle repairs, servicing and MOT testing. We are also an Independant Skoda specialist. Serving the village of Steeton and surrounding areas of Keighley, Silsden, Crosshills and Kildwick we have been providing reliable and honest work to our garage customers for over 20 years. From our fully equipped Garage conveniently located on the outskirts of Steeton we can offer a comprehensive service for your car from general annual services to Timing Belt checks, help with new or flat tyres and clutch repairs/replacements. Together we have decades of experience riding and repairing bikes and now we are offering that service to our customers in Steeton and the Aire Valley. The garage has a dedicated area for bikes with 3 ramps/lifts and a dedicated tool shop to allow us to perform your repairs or service at the standard you expect from Philip Lund mechanics.

Unit 1 Aireburn Garage, Keighley Road, Steeton, BD206RH

Bolton Tyre & Exhaust Ltd (OPEN 7 DAYS)

4.0/5

Bolton Tyre & Exhaust Ltd. Is a reputable vehicle servicing and repair centre based in Bolton, Lancashire. Being an established vehicle service and repair centre we specialise in all aspects of vehicle repairs, incl exhausts shock absorbers, vehicle diagnostics, vehicle air conditioning systems, MOT Testing, and vehicle servicing and repairs to all makes and models of cars and vans. We focus on providing excellent vehicle services to all customers throughout Bolton and the surrounding areas of Bury, Walkden, Leigh, Wigan, Chorley and Blackburn.

Topping Street Off Brownlow Way, Halliwell, Bolton, BL1 3UP

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.