The Dangers of Misfuelling Your Land Rover

Misfuelling any vehicle can be a catastrophic error and end up with huge costs for you to cover to get your Land Rover up and running again. Luckily the Land Rover misfuelling protection device exists to help stop it from happening, but, it is still possible to misfuel a Land Rover.

It should be noted that the device is a protection device and not a prevention therefore, even with it in the vehicle you can still fuel a Land Rover incorrectly.

So, in this month’s blog, we explain what misfuelling can do and how the device works in your Land Rover so you can avoid the potential damage that misfuelling creates.


What is misfuelling?

Misfuelling is simply putting the wrong type of fuel in your Land Rover. Putting petrol in a diesel vehicle and vice versa.

It sounds almost impossible, especially if you have driven your vehicle for a long time but it has been reported in the past that the AA receives almost 80 calls a day due to fuel-related problems encountered by drivers!

What damage does misfuelling do?

Misfuelling can be extremely damaging to your vehicle and at times the costs to rectify a misfulled Land Rover can run into the thousands! The damage can be so severe that there is every chance your Land Rover will not be salvageable. Below, we show the key areas that can be damaged through misfuelling.

Fuel pump

If petrol makes it into a diesel vehicle, for example, imagine your vehicle running without any oil. The petrol acts more like a solvent than a lubricant and as a result, builds up metal on metal friction. Thanks to this, small parts of metal may chip away and get into your fuel system causing significant damage. For this alone you could be looking at £500 to have it repaired and, in some cases, even more!

The filter

If the incorrect fuel has made its way to the filter, it will certainly need replacing. Filters exist to prevent contamination in the engine but with the wrong fuel now there, the contamination has happened and the only way to be rid of it is to change the filter.

Fuel lines

With the incorrect fuel heading down the fuel lines, it will inevitably leave a trace of its presence. Sometimes, flushing them through is sufficient but in some cases, they will need replacing completely.

Fuel injectors

Fuel injectors have small holes within them and if the wrong fuel has been put into a Land Rover, these holes can soon be blocked by the small metal fragments we mentioned earlier. This can cause severe damage to the vehicle and could see you spend close to £1000 to fix it!

How does the Land Rover misfuelling protection device work?

The Land Rover misfuelling protection device was created to help people avoid the problems we have mentioned above and the costly repairs that come with them. It works by sealing off the fuel tank so that the incorrect fuel cannot be put into the vehicle.

For example, if you were to attempt to use a petrol pump rather than the required diesel, the petrol pump will not fit the same. Its shape and size activate a spring that closes off the filler neck stopping the incorrect fuel from getting any further. You will be able to tell it is closed when you see the yellow device sealing off the route of any fuel.

This is a great way to stop misfuelling and can save you from very expensive repairs, but it has been found to not always be 100% foolproof. Should the pump be inserted at an angle or not pushed far enough in to cause activation, it can leave you filling your Land Rover with the incorrect fuel for quite some time until you realise your mistake. It is at this point that it is too late!

This also means that it is now hard to fuel again when you need to. The device when activated closes off the path for any fuel so you will need to reset it. This can be done with the reset tool provided with your Land Rover.

Land Rover misfuel reset tool

Depending on the model of Land Rover you own, the misfuel reset tool may be in different places. In most cases, you will find it in the provided toolbox or the boot. It is yellow in appearance and, for want of a better description, looks like a plastic stick!

To use it, simply insert the tool with the teeth facing upwards as far as it will go into the filler neck. Then simply push down on the top of the reset tool to engage the teeth.

Once engaged, do not twist, or wiggle the device around, it could break the teeth and leave you with a longer-lasting problem. You can now slowly pull the tool out to reset the misfuelling protection device. You should now see the yellow passive misfuelling device is no longer visible.

What should you do if you have misfuelled your Land Rover?

If your passive misfuelling protection device has not been activated or your Land Rover is old enough not to feature one, you may have filled the tank with the wrong fuel. Do not start the vehicle!

Damage is almost instant, and the biggest damage is often caused the moment the key is turned. If you are on the forecourt, inform the petrol station staff and see if you can push your Land Rover (with assistance) to safety. Only do this if you feel comfortable and safe doing so.

You should then look for a mechanic that can flush your fuel.

If you have misfuelled and driven off, only noticing whilst on your journey that the error has occurred, pull over immediately to a safe space.

Contact a mechanic and give as much information as possible including what fuel, what model of Land Rover and how much fuel you may have filled up with. This will help them to assess the potential damage caused.

Signs of misfuelling in a Land Rover

The signs of misfuelling vary slightly between petrol and diesel vehicles so it is important to know the key indicators.

Signs a petrol vehicle has been misfuelled

If you have filled your petrol Land Rover with diesel you may notice the following:

  • Your engine may not start at all regardless of how many times you try
  • Your engine could suddenly cut out
  • Excessive smoke could come from your exhaust
  • Your engine could misfire and cause sudden movements of your vehicle.

Signs a diesel vehicle has been misfuelled

If you have filled your diesel Land Rover with petrol you could notice the following:

  • A knocking sound whilst you drive
  • An unusually slow acceleration
  • A sudden stop of the engine working
  • Excessive smoke coming from the exhaust
  • The engine warning light turning on


If your Land Rover has been misfuelled you may have had a fuel flushing to help clear it out but you may still benefit from a Land Rover servicing. Our team at Roberts Country Vehicles are experts in keeping your Land Rover roadworthy. We work to the Land Rover service plan and only use the latest manufacturers’ diagnostics to make sure that your Land Rover is in the best condition possible. With a saving of up to 40% on main dealer prices, why not contact our team today to find out more. We even offer Land Rover MOTs at our Kent Land Rover Service Centre so you can benefit from a full and comprehensive care package for your vehicle.