What happens when you put diesel in a petrol vehicle?

Although it is not as damaging as putting petrol in a diesel vehicle, putting diesel in your petrol vehicle can prevent your engine from running.

Since diesel weighs more than petrol, it will sink to the bottom of your  fuel tank. This means that as soon as the car starts, the diesel will make its way through your electric fuel pump and fuel lines and into your engine, possibly damaging the fuel pressure regulator and fuel injectors in the process. Your engine won’t be able to burn diesel, meaning that the engine will cease to work properly. 

Once you start driving, the car will run fine for a few kilometers. This will continue into all the petrol in the fuel lines is used up. At this point, the vehicle’s engine will not be able to run. Fortunately, the mechanical parts of your engine (such as pistons, piston rings, bearings, valves) are unlikely to be damaged at all, but because the diesel won’t burn in a petrol engine, then the vehicle will not run until the diesel is removed from the engine, fuel lines. fuel pump and fuel tank.  


What should you do if you put diesel in a petrol car?

Ideally, you will notice your error before you start the engine. We recommend that you get your car towed to a mechanic immediately (and do not start the engine). This will prevent the diesel from circulating around your vehicle. When the car starts, diesel can find its way into your car’s fuel pump. fuel lines and engine, making it difficult to remove.

Learn more about what to do >


How is diesel removed from a petrol engine?

In order to get your car running again, all of the diesel fuel will have to be removed from the engine. This process is called a diesel flush, which often consists of:

  1. Draining the petrol tank of all fuel.
  2. Ensuring the fuel lines, fuel rail and fuel regulator do not have any diesel fuel in them.
  3. Removing the fuel injectors from the vehicle and cleaning them. In some cases, the fuel injectors will need to be dismantled, or even replaced. 
  4. Reinstalling the fuel injectors and attempting to run the vehicle with petrol.

Altogether, the removal of diesel fuel can be a lengthy process. The exact amount of time required often depends on whether you started the engine or turned the ignition key on (so the fuel pump ran) with diesel in the fuel tank. If not, then a fuel tank drain and refill with petrol will probably be enough to fix the issue.  The old petrol contaminated with diesel fuel will need to be disposed of correctly, as it can’t be used safetly in any engines, so often mechanics will need to pay 


Diesel flushing service in Hamilton

Have you accidentally put diesel fuel in your petrol vehicle fuel tank? If so, we can perform a thorough flush on your vehicles fuel lines, removing all diesel from your fuel lines, tank, fuel rail, fuel pump, fuel regulator and injectors. 

Our qualified, experienced and skilled mechanics can remove, clean your car’s fuel injectors, preventing the diesel from remaining inside your engine and stopping your engine from running.

For effective diesel removal/flushing in Hamilton, contact Grimmer Motors today!


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