Red light spells disaster

One third of drivers would ignore a red oil warning light and risk blowing up their engines

  • £1,000+ garage bills for ignoring red warning lights can put you in the red, says the AA
  • Familiarising yourself with your vehicle’s symbols can save you time, inconvenience and money
  • A matter of seconds is the difference between an oil warning light and a badly damaged engine
  • Red warning light

    Thursday 17th August 2023

    An AA survey of 12,598 drivers in late July revealed that only three in 10 (30%)* would stop immediately if the oil pressure light came on, while another third (33%) would have driven on to a place of safety before switching off the engine. Continuing to drive a vehicle with an oil pressure light illuminated can lead to catastrophic engine damage which often results in an eye-watering garage bill.

    A matter of seconds is the difference between an oil top-up and a badly damaged engine, often resulting in a four-figure bill and can also leave you stranded at the roadside – or worse if driving on a ‘smart’ motorway.

    Oil level warning lights (often confused with oil pressure lights), illuminate when an oil top-up is required – these are usually amber instead of red, and mean the vehicle can be driven until a top-up can take place, however, one in 10 respondents said they would stop immediately if this light came on.

    Similarly, one in four (24%) of respondents said they would continue to drive with a coolant temperature warning light illuminated until they found somewhere safe to stop, while a further 25% said they would wait until the light came on, before checking what it meant. Like an engine oil pressure light, driving with a coolant temperature light on can lead to major engine damage and time off the road, in addition to a large bill.

    “Learning what warning lights mean can ease the strain if they come on when driving”
    Tony Rich, former AA patrol of the year

    Last year, the AA, the UK’s largest driving organisation, attended more than 17,000 vehicles where the driver had cited a dashboard warning light as the reason for their callout. On average, nine out of 10 of these vehicles were driven away, with one in ten of those only needing some reassurance on what the light referred to – for these drivers, a little research could have saved them the time and inconvenience of reporting a ‘breakdown’.

    As more features are added to modern cars, the list of dashboard warning symbols will grow. Knowing what’s what, when it comes to dash symbols and warning lights, can leave you better prepared if one of the lights or symbols suddenly illuminates when driving.

    Red light spells disaster

    A red warning light normally means immediate action is required and ignoring it can lead to vehicle damage and leave you stranded.

    An amber or orange warning light signifies a vehicle fault but usually means that it’s safe to drive to a garage for further checks. That said, a flashing amber engine management light (EML), signifies an engine misfire – meaning that the vehicle will need to be switched off as soon as possible to prevent damage to the vehicle’s catalytic converter or diesel particulate filter (DPF), reinforcing the need for drivers to familiarise themselves with the meaning of warning lights.

    The same survey revealed that only a third (32%) of respondents said that they would recognise a charging system warning light (this is normally a battery symbol) and would get to a place of safety before stopping if it came on. This warning light refers to a battery charging or alternator fault, but as most alternators are belt driven, it doesn’t necessarily mean that the alternator is broken and could indicate a broken fan belt or belt pulley system issue, so it’s important to stop the car and switch off as soon as possible to prevent possible engine damage or electrical issues.

    Tony Rich, former AA patrol of the year, said: ”With the sheer amount of information and warning symbols available on many modern dashboards, it’s ok to feel daunted. Learning what the main warnings lights and symbols mean before you actually need to know, can ease the strain if they come on when driving.

    “Trying to access information on warning lights if you’re in a rush, or when flustered, can lead to confusion around what the warning means. For example, knowing the difference between a light telling you that an oil change is due rather than the engine’s oil pressure being critically low can save you waiting at the roadside for help to arrive, as much as it can save you a costly trip to the garage. There is lots of information available online or on the free AA breakdown app and within your vehicle's handbook (if available).

    “Carrying out regular vehicle checks such as oil and coolant levels and tyre pressures and condition can also give you an indication of faults that may be developing, meaning these can be fixed before the need for a warning light to spoil your day.”

    *Yonder conducted an online survey of 12,598 UK adults aged 18-65+ between 18th to 25th July 2023. Data is weighted to be representative of the population of the UK. Targets for quotas and weights are taken from the PAMCO survey, a random probability survey conducted annually with 35,000 adults. Yonder is a founding member of the British Polling Council and abides by its rules.