If you notice any problems with your vehicle, it’s important to book it in for a diagnostic check. If the issues are left untreated, then it can lead to costly repairs and breakdowns. In this guide, we’ll be explaining some common signs to look out for and what a diagnostic check actually does.
Signs Your Car Needs a Diagnostic Check
- The engine management light is on
- Any strange noises
- Changes in performance and fuel efficiency
- Difficulty starting the engine
- Unusual smells or smoke
What is a Diagnostic Check?
A vehicle diagnostic check is used to identify specific issues with the vehicle which are difficult to see visually.
Modern cars have what’s called an engine control unit (ECU). The ECU is the car’s onboard computer which receives information from various sensors to monitor and control the engine. During a diagnostic check, a scanner is connected to the onboard diagnostics port. This test reveals error codes to help pinpoint the area affected and the severity of the issue.
5 Signs Your Car Needs a Diagnostic Check
The Engine Management Light is On
If there are any issues with your car’s engine, then the engine management light (EML) will become illuminated on your dashboard. There are different types of light to look out for and all of them will result in an MOT failure. Here’s a quick summary of them.
| Engine Management Light (EML) | Seriousness | Should I Still Drive? | What to Do |
| Steady Amber | Moderate | Yes | Finish your journey but get the car checked by a mechanic as soon as possible. |
| Flashing Amber | Critical | No | Stop the car as soon as possible in a safe place and call for breakdown cover. |
| Steady Red | Critical | No | Stop the car as soon as possible in a safe place and call for breakdown cover. |
In all cases, if you notice an EML on your dashboard, the vehicle will need a diagnostic check to identify the problem and how to fix it. It’s important to do this as soon as possible as otherwise the car can breakdown suddenly, and any problems can be exacerbated leading to expensive repairs. Some common causes are issues with the spark plugs, catalytic converter, sensor problems, fuel pump, DPF filter and EGR valve.
Strange Noises
If you notice any strange noises, it’s vital to get these checked by a mechanic who can run a diagnostic check to identify the problem. Unusual noises can include:
- Engine knocking or rattling
- Rattling underneath the car
- Clunks or creaks when going over bumps or turning corners
- Squealing sounds when starting up or accelerating
Strange sounds can be caused by a multitude of issues, and running a diagnostic check will pinpoint the problem and how to fix it.
Changes in Performance & Fuel Efficiency
Another sign to look out for, is any decrease in the car’s performance or fuel efficiency. Often these will be accompanied by the engine management light, but sometimes they might not activate it, so it’s always a good idea to keep an eye on your vehicle’s performance.
Some issues that can cause a decrease in either performance or fuel efficiency (and sometimes both) can include:
- Worn or clogged calalytic converter
- Blocked DPF filter
- Dirty or faulty air intake system
- Fuel pump failure
- Worn spark plugs
- EGR valve failure
As there are so many potential causes of a reduction in performance and fuel efficiency, a diagnostic check is crucial to pinpoint the problem.
Difficulty Starting the Engine
If you’re having issues starting up the engine, or notice that it’s frequently stalling, then it’s time to book the car in for a diagnostic check. This can be caused by several problems including worn spark plugs, a weak battery, a faulty starter motor or wiring issues. Again, the number of potential causes is considerable, and a diagnostic check offers an efficient way to identify the issue so it can be fixed quickly.
Unusual Smells or Smoke
If you notice any unusual smells or excessive smoke being produced by the exhaust, then get your car booked in for a check. This can save a lot of money in the long-term, as the problem can be identified more quickly, preventing costly future repairs.
Unusual odours can range from burning smells, which can indicate overheating or electrical problems, to sweet odours which signal a coolant leak. A rotten egg smell is often caused by an issue with the catalytic converter. The specific problem can be tricky to diagnose without a diagnostic check, so booking the vehicle in as soon as possible is crucial.
Book a Diagnostic Check in Worcester
Here at Recharged Automotive in Worcester, we have over 30 years of experience fixing cars so you can rest assured that your vehicle is in good hands. Our highly-trained technicians can work on petrol, diesel and electric vehicles, and we pride ourselves on our commitment to providing excellent customer service. If you need a diagnostic check, get in touch by calling 01905 464812.