Misfuelling can be an expensive error, but mistakes happen to the best of us. According to the RAC, around 150,000 people put the wrong fuel in their car every year. So, you’re not alone.
If you’re clued up on how to deal with putting the wrong fuel in your car, then you can significantly reduce the damage to your engine (and your wallet).
Here at Eurorepar, our experts have created a misfuelling guide, detailing what to do if you put petrol in a diesel car and vice versa, what happens inside the engine, and tips for how to prevent a fuel mistake from happening again.
If you realise you’ve put the wrong fuel into your car and haven’t turned the ignition yet – don’t!
Starting the engine can cause the wrong fuel to circulate through the system, potentially leading to more damage. If you are still at the petrol station, ask for assistance to push your car to a safe location or arrange for your car to be towed to a repair shop.
The most common solution is to drain the fuel tank and fuel lines to remove the contaminated fuel. You must have this done by a professional, as it involves the use of specialised equipment and safety precautions. They may also need to replace parts of the fuel system if they have been contaminated.
The mechanic will inspect your car’s engine and fuel system to check for any damage that may have been caused by using the wrong fuel. Once the fuel system has been cleared and the repairs have been made, you can then refill the tank with the correct fuel.
Keep an eye out for any unusual behaviour or performance issues and if you notice anything, consult a mechanic.
Top Tip: It’s a great idea to have a breakdown kit in your car at all times.
So, what are the ‘symptoms’ of putting the wrong fuel in your car?
· The engine won’t start – in some vehicles, the engine will not start at all. However, this isn’t always the case. If this does happen, seek assistance from the attendant at the fuel station to check whether you have put the correct fuel in.
· Engine cut out – you might be able to start your engine, only to have it cut out after a few minutes and not restart.
· The engine warning light appears – you may also see the engine warning light appear on the dashboard.
· Smoke from the exhaust – if you manage to start your engine but see an excessive amount of smoke coming from the exhaust, this is likely a symptom of misfuelling.
· Strange noises - you might notice a loud knocking sound while accelerating.
· Strong odours – unusual smells might star coming from the exhaust or engine area.
This is the most common kind of misfuelling as the petrol nozzle can fit into the diesel filler neck, making it an easy mistake to make. It is also the more damaging type of misfuelling and can require a brand-new engine if you’re unlucky.
Diesel acts as a lubricant, helping the fuel pump to send fuel where it needs it. Petrol is a ‘thinner’ fuel, so when it’s pumped into a diesel engine, it will do the opposite by increasing the friction between parts and cause any repair costs to shoot skywards.
The diesel pump nozzle is bigger than the petrol one, so this is a less common fuel mistake. However, if you do manage to put diesel in a petrol car, it will go into the tank, clog the fuel system and stop the car from starting. Although it is a big inconvenience, this can be easily resolved and shouldn’t result in any lasting damage.
Once the ignition key is turned, the wrong fuel is going to be pumped straight through the engine and cause damage. So, if you find you have already started your car, you must stop and turn the engine off as soon as possible. However, your car may have already experienced extensive damage, so you may find yourself unable to use your car after the wrong fuel has been taken out, without taking it to a garage for further repairs first.
This could take anywhere from a couple of minutes to a few hours. It is all dependent on how much fuel has been put into the tank and how accessible the tank is.
· Be vigilant – get in the habit of double-checking the fuel pump before you use it every time you fill up at a petrol station.
· Remove distractions – put your phone away, turn off the radio and take your time when at the fuel station. Mistakes are more likely to happen when you’re distracted or in a rush.
· Place a ‘petrol’ or ‘diesel’ sticker on your fuel cap – this will be a visual reminder of which fuel to use.
· If you have a diesel vehicle, buy a different-shaped filler neck – this will make it more difficult to insert the smaller petrol nozzle by mistake.
Hopefully you won’t need to know what to do if you misfuel your car, but if you do, we hope our guide has helped you. If you experience any of these issues, pop into your local garage and a Eurorepar professional will be able to help you with expert advice, or to check on the overall health of your car, schedule a service or MOT.
