Car engine problems: What to do if you have trouble on the road

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Engine problems
How it works
Engine management
Temperature
Oil
Other issues
FAQs

If you run into car engine problems on the road, you need to know what to do. Sometimes it’s okay to keep driving – at least to the nearest garage – but other times you’ll need to pull over straight away to sort out the issue or get help.

These days, most cars are equipped to let you know straight away if something’s wrong with the engine. They do this by displaying a whole host of little warning lights on the dashboard. Understanding what these mean and what to do when they come on is the best way to stay safe and minimise any damage to your car.

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How a car engine works

Don’t worry – we won’t get too technical here. But it’s always good to know roughly what’s going on in a car engine, because it’ll help you understand what mechanics are talking about if you have a problem.

Here’s a quick overview of how a petrol or diesel car engine works:

  • The car burns fuel to create energy – or, more accurately, a ‘force’. This gets called ‘torque’ in the technical world of cars.
  • This force, or torque, gets applied to the car’s wheels, making them turn – and voila, you have a moving car!
  • A chain of reactions have to happen to get to this point, though – the big event being the ignition of a mixture of fuel and oxygen.
  • This happens over and over again – it’s basically like a series of mini-explosions going off.
  • These mini explosions make a set of pistons move up and down inside metal tubes (cylinders).
  • The movement from the pistons makes the car’s ‘crankshaft’ (a hardened steel shaft) spin. It’s this that powers the car’s wheels to turn.

Okay, so this is a pretty simplified version. But a few big takeaways to keep in mind are:

  • There are a lot of very intricate moving parts in a car’s engine – if any of these are faulty or not working properly, you’ve got problems.
  • All of this activity generates a lot of heat, which is why cars have a cooling system to regulate the temperature of the engine. If anything goes wrong with this and the engine overheats – you’ve got problems.
  • It’s also important for all these moving parts to be well lubricated (otherwise they’re just going to grind away at each other, ouch). Hence the need for engine oil. If there’s a leakage or another issue with the oil and levels drop too low (you guessed it) – you’ve got problems.

A good idea to avoid engine problems is to keep on top of car maintenance.

Keeping on top of car maintenance will reduce issues
Keeping on top of car maintenance will reduce issues
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Engine management light issues

Now we’ve covered the basics, below is a breakdown (excuse the pun 🤷) of all the different engine issues to be aware of and which car dashboard warning light represents them.

The engine management light (sometimes called the ‘check engine’ light) is an engine shaped light that’s usually amber or yellow in colour. There are lots of different reasons that this light can come on – some more serious than others.

It could simply mean that your car’s fuel cap is loose (a quick fix). Or it could mean that a part of your engine is faulty or in need of replacing. For example, the spark plug could be faulty, there could be a malfunctioning oxygen sensor, or there could be an issue with the catalytic converter.

If the check engine light is amber or yellow and it’s not flashing, you should be fine to keep driving at a reduced speed – at least to get home or to a car garage. If you can’t get home or to a garage within a few miles, you should call for assistance.

If the light is flashing or red, you should pull over as soon as it’s safe to and call for breakdown assistance. This is because a flashing or red check engine light usually means there’s something seriously wrong with the engine – which could mean the car is dangerous to drive, or at risk of very serious damage.

If the light is amber or yellow and not flashing there are a couple of things you can check yourself before heading to a mechanic:

  • Check the fuel cap – if it’s loose, tighten it. If it seems like it’s loose but won’t tighten, it might need replacing.
  • Think back to whether or not you might have put ‘bad fuel’ in. Say your car is designed to run on premium fuel (octane grade 91 to 94) – the engine might struggle to perform properly if you accidentally put in standard fuel (octane level 87). In this case, you should get your tank drained by a mechanic as soon as possible.
  • If you’re handy with cars, you could use an OBD-II scanner to run a diagnostic test on your car. This will give you a code, telling you what the specific problem with the engine is. If you have no idea what we’re talking about here (no shame in that) – it’s probably best to just go to a mechanic!

If you don’t get anywhere with the above, you should take your car to a mechanic as soon as possible. If you keep driving around day after day even though the check engine light is on, your car could end up getting seriously damaged… costing you way more than if you’d got it checked straight away. Nobody wants that 😬

Engine temperature issues

Engines naturally create a lot of heat when they’re at work. Usually, your car’s cooling system will regulate the temperature of your engine – but things can go wrong, and it can end up overheating. For example, there could be a leak in the cooling system, or the engine could simply overheat in very hot weather.

Whatever the exact cause, an overheating engine can quickly turn into a serious problem. If your car’s onboard computer detects this is happening, the engine temp warning light will come on. It’ll be a red symbol – either a thermometer sitting in waves of liquid or just the word TEMP.

If you see the engine temp warning light, pull over as soon as you safely can. Turn off the engine for around 20 minutes to allow the engine to cool. At that point (and if the engine temp warning light has switched off), you should drive to the nearest garage for an inspection. They’ll be able to tell you why the engine was overheating, and what next steps to take.

Engine oil issues

If your car’s oil pressure warning light comes on (that’s a red oil or ‘genie’ can symbol with drop coming out), your car could be at risk of serious damage.

This means that your car’s oil pressure has dropped to dangerously low levels – or has even run out.

This might be because of a range of different reasons. The engine could be burning oil, there could be a major leak, the oil pump could be faulty, or the oil filter could be clogged. Whatever the exact cause, this is a serious problem. Without enough oil, the engine will get very damaged very quickly.

Turn the engine off as soon as you can safely pull over. Let the engine cool down, then – if you feel comfortable doing so – check your car’s oil levels:

  • Open the bonnet.
  • Find the dipstick – look for a tube to the side of the main engine block.
  • Remove the dipstick and wipe off any oil with an oil rag.
  • Put the dipstick all the way back in the tube, then pull it out again.
  • Check to see if the oil sits within the two markers for upper and lower oil levels.

If the dipstick test shows the oil levels are too low, you’ll need to top up the oil straight away. If you don’t have any oil, you’ll need to call for breakdown assistance.

Once you’ve topped up your oil, turn on the car’s engine to see if the oil pressure warning light has turned off. If it has – woohoo! You can drive. But you should get your car checked by a mechanic as soon as possible to find out why your oil levels dropped in the first place. If the light comes back on at any time – you’ll need to top up the oil again. Never drive when the oil warning light is on.

If the dipstick test shows the oil levels are fine, on the other hand – you’ve got another problem. Unfortunately, the only thing to do here is to call breakdown assistance.

The engine oil light is one of the most serious on the dashboard
The engine oil light is one of the most serious on the dashboard

Other engine issues

Although modern cars are very good at warning us about problems, their internal computers aren’t immune from their own issues. So it’s always good to know the actual, physical signs of engine problems – just in case one of those little warning signs isn’t working.

If you notice any of the below signs, get your car checked as soon as you possibly can:

  • Car vibrating or shaking when idling.
  • Car suddenly using a lot more fuel than usual.
  • A loss of power when you’re driving (your car feels like it’s not accelerating as well).
  • Car stalling when idling.
  • Engine making a lot of noise – like popping, stuttering and hissing.

Engine problem FAQs

How do you reset an engine dashboard light?

Sometimes warning lights get stuck on ‘on’, even when the issue is fixed (or when there was no issue to begin with). If you’re totally sure there is no issue with your engine you can try to remove the light by disconnecting and reconnecting your car’s battery.

Or you could plug an OBD-II scanner into your car’s OBD port and clear the light that way. Another technique to try is to switch the car’s ignition to the ‘on’ position then off again 3-5 times in a row.

Can you pass your MOT with an engine light on?

No – your car will never pass an MOT if there is an engine light on the dashboard. So you’ll want to get that seen to before your appointment.

Is it safe to drive with an engine dashboard light on?

If the engine light is amber and is not flashing you should be okay to drive briefly. You should try to go at a reduced speed, though, and avoid heavy acceleration. Get to a mechanic as soon as you can to get it checked out properly.

If you get a flashing or red engine light on your dashboard, you should pull over as soon as you safely can and call for assistance.

Do you need to call breakdown cover for an engine light?

If the engine light is amber and is not flashing, you should be fine to drive for another couple of miles. So if you can get home or to a garage within that distance – you can probably avoid calling for breakdown assistance.

If you get a flashing or red engine light on your dashboard, you’ll need to pull over as soon as you can and call for assistance.

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Updated on 13th September 2023