There are few things worse than failing an MOT. Arguably, one of those is seeing your engine light come on. But do they go hand-in-hand?
Unfortunately, your car will fail its MOT test if its engine light is on. We’re here to explain how you can fix things when this happens.
Does The Engine Light Being On Fail Your MOT?
Yes. If you take your car to have its MOT test and the engine light is on, it will be an instant fail. This light indicates that something could be wrong with the vehicle that means it’s unsafe, or it might mean that the car is producing too many nasty emissions.
Don’t forget, your car can fail its MOT because of bad emissions! Here’s what you should do if that happens.
What Is The Engine Light Actually For?
As with any mechanical problem, it’s best to fully understand what’s going on before you try and get it fixed.
The engine management light, as it’s formally known, is one of the many lights that might pop up on your dashboard from time to time. This one indicates a problem with your engine. Unfortunately, the engine light can often mean that something serious is wrong with your car.
However, that’s not always the case. Simple problems might also cause the engine light to illuminate, so don’t panic!
Amber, Blinking & Red Lights Explained
You might have seen your engine management light pop up once or twice and started to worry, but if you’ve only had it light up amber in colour, the situation could be worse.
Amber
Amber means that something is wrong, but that the problem is not going to cause you any immediate concerns or danger. You can continue to drive around with your amber EML on, but should probably try and get to the root of the issue soon.
Blinking
A blinking or flashing amber light means the problem is more serious. However, it’s still not likely to be a life or dead situation. You should, however, think about taking the car to a professional to have the matter investigated as soon as you can.
Red
A red light is much more severe. If your EML is on, and it’s red, you should pull over as soon as it’s safe to do so and call your recovery service to come and collect your car. Continuing to drive it could do fatal damage to your vehicle, and may even result in a dangerous accident if your car fails at the wrong time.
Can I Drive My Car After An Engine Light MOT Fail?
As long as your current MOT certificate is in-date, then yes, you can drive your car even if it’s failed its new MOT test because the engine light was on. That’s because an amber engine light on the dashboard is only considered a ‘major defect’ rather than a ‘dangerous defect’.
Dangerous defects mean you cannot drive your vehicle away from the MOT test centre until the issue is fixed. We’ve got an in-depth explanation of the everything from advisories to dangerous defects here.
What Engine Problems Can Cause The Light To Come On?
There are quite a few problems that can cause the engine light to illuminate on your car’s dashboard. Here are some of the most common:
- Oxygen sensor – This measures the air in your fuel to ensure it’s kept at an appropriate level. If there’s too much or too little air in the fuel lines, the engine management light (EML) will come on. However, the light might also come on if the sensor itself breaks.
- Catalytic converter – One of the most expensive parts of any car, this helps reduce the emissions that come from your vehicle to a less harmful standard. If it breaks, your engine could be in danger of damage.
- Diesel Particulate Filter (DPF) – This reduces the amount of soot in your exhaust, but can become blocked. If this happens, your emissions will be much more harmful and your EML may turn on. Don’t panic, though; there are ways to unblock it!
- Mass airflow sensor – This part tells the car how fuel needs to be sent to the combustion chamber to keep the car running properly, but if it stops working as it’s supposed to, it could result in engine damage and the EML illuminating.
- Spark plugs & coil pack – These parts work in tandem to kick off the combustion process and keep the car moving smoothly as it drives. However, if they start to malfunction, the car might become juddery and the EML can come on.
- Oil – If your engine oil is old, or even if the level of oil in your car is drastically low, the EML might come on.
If your engine light is on, you should probably read these helpful guides too.
If your engine light is on, you should probably read these helpful guides too. How Much Does It Cost To Fix An Engine Light Problem?
Generally speaking, you’re looking at several hundred pounds. Of the above, an oil change will be the cheapest – a bottle can be as cheap as £10 in most places. Spark plugs and coil packs are also an easy fix that’s relatively cheap.
Moving up, you’re probably looking at £100 to £500 for problems involving sensors, and up to £1,000 if you’re in need of a replacement catalytic converter. However, the big money problem lies in the DPF… Diesel drivers could up paying thousands of pounds for a replacement diesel particulate filter. Luckily, they often have their own warning light on the dashboard which should light up separately!
Engine Light FAQs
Will my engine light go off on its own?
Usually, no. If the engine light has come on, it’s because there’s a problem with the car. However, turning something off and on again can work wonders for any machine. It is possible for your engine light to simply be on one day and off the next – but don’t assume whatever issue caused it has fixed itself!
Can I turn the engine light off myself?
You can, but probably shouldn’t. On some vehicles, turning off the electronics (with a partial turn of the key in the ignition) and turning it on again several times can clear the engine light.
A more sensible way of doing it is to invest in an on-board diagnostics kit (OBD) which you plug into your car. Once connected, this device will read your car’s systems and attempt to tell you what is wrong with it! Not only is this a good way of actually figuring out what the problem is, you can also clear the engine light.
Why is my engine light on but my car feels normal?
Not every problem with your vehicle will have an immediate or obvious impact on the way it drives. The same goes for issues that cause your EML to illuminate. The thing is, if these problems are left alone, they will almost certainly get to a point where they do impact the car’s performance and might even end up needing a massive repair job.
Does the engine light mean I need to scrap my car?
Not necessarily, but it might… It depends on the specific problem that’s causing your engine light to come on in the first place, plus your own financial situation. If you’ve got plenty of cash to put towards repairs, you can absolutely keep your car on the road for a longer – even if it means having to do a total engine replacement!
However, if you don’t have the financial freedom for that, you might need to consider scrapping the vehicle instead. Here at Scrap Car Comparison, we specialise in getting drivers the best prices for their old, unwanted or even broken cars – even ones that have failed their MOT test! Get a quote today and see how much you could get for your old car. There are no hidden fees, and free collection of the vehicle is always included.
MOT Failure Hub
If you have, or expect to, fail you next MOT test there are a number of options, and important things to know. Luckily, we have expert guides on all MOT failure topics.
Can you drive car after a failed MOT
There is a 10 day grace period where it can be driven, with conditions that the car is safe.
Retesting and appealing an MOT test
If you are not happy with you test results and believe there to be mistake, find out your next steps here.
Driving a faulty car before your MOT test
If you know your car would fail an MOT test, you have a legal a duty to have that car repaired. Find out more.
Failing your MOT on emissions
Failing your MOT on emissions is not usually something we would expect. Find out everything you need to know here.
Or, visit our MOT failure hub for guides on everything related to MOT, and how to navigate your options after a fail.
Sell your MOT failed car
If you want to get rid of a car which has failed it’s MOT test, or is damaged beyond repair, you can get an instant and free quote online. Simply add your reg number and postcode and we can find you a salvage buyer in your area.
