Many times, we put in the wrong fuel in our cars (misfueling) i.e., filling diesel in a gasoline engine or gasoline in a diesel engine. Misfueling badly affects the vehicles’ fuel delivery system and its performance.
Let’s see in this article how each misfueling situation affects your vehicle and what measures to take when this situation arises.
Diesel in gasoline engine
Filling diesel in gasoline engine is very unlikely, because the nozzle of diesel pump is larger than the gasoline pump and the nozzle does not fit in the gasoline tank of the car except for old cars that are manufactured 25 years back.
Damage it causes
Diesel in gasoline engine is not a severe problem. It can be fixed. However, if the percentage of diesel is more, it leaves some negative effects.
First of all, it decreases the octane rating, which is not good for the car (Octane rating measures the ability to resist pre-ignition and knocking).
As soon as diesel enters your gasoline engine, spark plug fails to ignite and so engine doesn’t start.
If the diesel in gasoline-diesel mixture is less than 10%, you may be able to turn on the ignition and your car starts. However it causes knocking and pinging, and emits more smoke.
With more than 10% of diesel the car doesn’t start and it is likely to damage fuel injectors and other parts of the fuel delivery system.
The moment you realize that you misfueled your car better not to start it or stop it (if you already did start) to prevent diesel from entering the fuel delivery system. Tow the car to the nearest mechanic and drain the tank. Make sure that the entire diesel is taken off from the tank, cranked out from the fuel lines and fuel injectors.
Re-fill the tank fully with gasoline after cleaning to further dilute diesel particles.
Consecutive re-filling of the tank fully with gasoline for 3 to 4 times after cleaning will wash off all diesel particles and car comes back to normal working condition.
Gasoline in diesel engine
Diesel engines are more vulnerable than gasoline engines. Gasoline in diesel engine causes great damage and leads to expensive repairs (can go up to $10,000). Moreover warranty of the car does not cover damage caused by misfueling.
Damage it causes
Filling gasoline in diesel cars is a very serious problem and causes severe damage to fuel injectors, fuel pumps and thus to entire fuel delivery system of the car.
The major problem arises not when you fill the car with wrong fuel but when you start the car with wrong fuel.
Even small quantity of gasoline in diesel engine can be problematic.
Gasoline acts as a solvent in diesel and high pressure gasoline elements reduce lubrication and cause catastrophic damage to the engine.
Never start your car when you fill in gasoline in a diesel car. Tow your car to mechanic to flush off all the gas in the tank and evaluate the damage to fix it.
If you realize it lately after starting the car, then get ready to pay high repair bills (sometimes its cheaper to replace the entire engine or buy a new car).
So, always be alert while fueling your car especially diesel cars. Also, do not take chance to start or turn on the ignition in either cases of misfueling. As mentioned earlier, better to tow your car to mechanic to flush off wrong fuel.
NOTE: Volkswagen is now providing misfueling protection guard to fuel tank caps to almost 209,500 Volkswagen cars in U.S. and 51,600 affected diesel vehicles in Canada. The guard attached to the fuel tank cap remains closed if the driver tries to insert gasoline nozzle by mistake.