What To Do If You Accidentally Put Gas in a Diesel Engine?

What To Do If You Accidentally Put Gas in a Diesel Engine?

Mistakes happen, and one common error among vehicle owners is accidentally filling a diesel engine with gasoline. This misstep can lead to potential issues if not addressed promptly. In this blog post, we’ll explore the steps to take and precautions to consider if you’ve inadvertently put gas into a diesel engine, providing essential guidance to mitigate potential damage.

Understand the Problem: Gasoline in a Diesel Engine

Putting gasoline into a diesel engine is a concern due to the differences in the two fuels’ properties. Diesel fuel acts as a lubricant and provides lubrication to various components within the diesel engine. Gasoline, on the other hand, lacks the lubricating properties necessary for diesel engine components and can lead to potential damage.

Don’t Start the Engine

If you realize that gasoline has been mistakenly added to your diesel engine, it’s crucial not to start the vehicle. Running the engine with gasoline in a diesel system can cause severe damage, including damage to fuel injectors, fuel pump, and other engine components.

What To Do If You Accidentally Put Gas in a Diesel Engine?

Seek Professional Assistance

Contact a professional mechanic or roadside assistance service immediately. Inform them of the situation, specifying that gasoline has been mistakenly added to the diesel tank. Professional assistance is crucial in properly draining and flushing the fuel system to minimize potential damage.

Do Not Drive the Vehicle

Avoid driving the vehicle if possible after gasoline has been introduced into a diesel engine. Even if the vehicle seems operable, driving it can exacerbate the problem and cause more significant damage to engine components.

Drain the Fuel System

The most effective solution is to drain the fuel tank and fuel lines completely. This process removes the contaminated fuel and prevents further mixing of gasoline with the diesel fuel. Professional mechanics have the necessary tools and expertise to perform this task safely.

Replace Filters and Fluids

After draining the fuel system, it’s advisable to replace fuel filters and other affected components, such as fuel lines or pumps, if necessary. Additionally, consider changing the engine oil to eliminate any gasoline contamination.

Preventative Measures

To prevent fueling errors in the future, consider using fuel-filler adapters or nozzle guards designed for diesel vehicles. These devices can help prevent incorrect fueling and serve as a reminder to use the appropriate fuel type.


Accidentally putting gasoline into a diesel engine can be a concerning situation, but swift and appropriate actions can mitigate potential damage. Remember not to start the engine, seek professional assistance, refrain from driving the vehicle, drain the fuel system, replace filters and affected components, and take preventative measures for future fueling. By following these steps and seeking expert guidance, you can minimize the impact of this mistake and ensure the proper functioning and longevity of your diesel engine.

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