Most motorists have been there; you’re happily driving along and your dashboard starts flashing. Of course, this usually happens at the most inconvenient time, but while it’s tempting to ignore it until you’ve got the time or money to deal with it, it’s wise to get the problem checked out before it becomes more serious. Here’s what that light could be telling you – and what you can do about it.
Loose cap - If your fuel cap is damaged or loose, it may affect the pressure in the fuel system, meaning that vapour can escape into the engine. Tightening the cap is a quick fix; if it’s damaged, you might need a new one.
Oxygen sensor issues - Your oxygen sensor monitors the ratio of air to fuel in the engine. If the sensor fails, you may see reduced fuel efficiency and emissions will go up. It can also cause problems with your catalytic converter, so it’s best to get it checked out and fixed as soon as possible.
Mass airflow sensor fault - The mass airflow sensor, or MAF, controls the amount of air that enters the engine. If this fails, you might notice that your car judders more than usual, or stalls. The fix could be as simple as cleaning the sensor, but it may need to be replaced.
Spark plug or ignition coil - Degraded spark plugs or failing ignition coils can cause your engine to misfire.
Catalytic converter – The catalytic converter helps to control emissions; when it fails, you will notice the smell of sulphur, or rotten eggs, as well as poor fuel efficiency and reduced acceleration. Replacement can be expensive, but regular servicing and maintenance can help you to avoid the cost.
Low oil pressure or coolant – If your vehicle is low on coolant or oil pressure, the engine could overheat, leading to serious damage. Make sure that levels are checked and topped up, especially if you are going on a long trip.
Air in the engine – If your engine has too much air in it, it may be sluggish to start, or cause overheating.
Sensor malfunction – Warning lights could come on as the result of electrical issues or problems with your sensors. Modern cars are much more complex than they used to be, and bad sensors or faulty wiring can cause lights to come on.
What to do if your engine light comes on
In the first instance, check for easy fixes, such as a loose or damaged fuel cap. If you’re at a loss, or not confident having a look yourself, head straight to your garage. Your mechanic will be able to see if there’s an obvious problem, or will be able to run a diagnostics test to find out. They’ll also be able to reset your vehicle’s computer so the light will stop coming on. Until you get to a garage, make sure that you drive cautiously and are vigilant for any unusual sounds or smells from your car.
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