What Happens When You Fill a Petrol Car with Diesel and the Solution

Filling a petrol car with diesel can lead to serious issues, as the two types of engines operate differently. Here's what happens and the steps to take if this unfortunate situation occurs.

What Happens

Fuel System Incompatibility: Petrol engines use spark plugs to ignite the fuel-air mixture, whereas diesel engines rely on compression to ignite diesel fuel. Diesel is thicker and has a higher viscosity than petrol, which can lead to clogging in the fuel injectors and fuel lines of a petrol engine.

Engine Performance: Starting the car after filling it with diesel can result in the engine struggling to run, misfire, or not start at all. Prolonged operation under these conditions can cause severe damage to the fuel system and engine components.

Potential Damage: Components such as the fuel pump, injectors, and spark plugs can be damaged, leading to costly repairs.

Solution

Do Not Start the Engine: If you realize the mistake before starting the engine, do not turn on the ignition. This prevents diesel from circulating through the fuel system, minimizing further damage.

Tow the Vehicle: Have the car towed to a professional mechanic or service center instead of driving it. Driving the vehicle may lead to further contamination and potential engine failure.

Drain the Fuel Tank: A qualified technician will need to drain the fuel tank completely to remove the diesel fuel. This step is crucial to prevent any residual diesel from remaining in the system.

Clean the Fuel System: After draining the fuel lines and injectors, they may need to be cleaned to remove any remaining diesel residue. This removes the risk of diesel-naturally lubricating components and avoiding further damage.

Refuel with Correct Fuel: Once the system is cleared and cleaned, refill the tank with the appropriate petrol.

Prevention and Alternative Solutions

To avoid this situation in the future, consider using fuel filler caps and labels that clearly differentiate petrol from diesel. Always double-check before filling up with the correct fuel.

Alternative Solutions:

Swap Fuel Tanks: Find the owner of the same model but diesel version and try swapping tanks with them. This is the most efficient solution but might be less feasible. Empty the Tank: Try and suck out as much diesel as possible. If the engine has not been cranked, drain as much out of the tank as possible and fill with fresh petrol. Engine Crank: If diesel is in the fuel lines, you may need to follow a more complex process. Undo the fuel line and crank the engine until fresh gasoline from the freshly filled tank works its way to the engine.

By following these steps, you can help mitigate the damage caused by filling a petrol car with diesel. Always take caution when filling your vehicle's fuel tank to ensure it is filled with the correct fuel.