What to Do If You Accidentally Put Gasoline in a Diesel Vehicle

Don’t start the engine or drive if you put gasoline in a diesel vehicle

If you mistakenly put gasoline in a diesel vehicle, don’t start it. If you started the engine and then realized your mistake, pull over right away and call a tow truck. Continuing to drive a diesel with a gasoline fill can cause major engine damage costing thousands of dollars.

Not starting the engine after the fill up will result is the lowest cost to fix. That will prevent the gasoline from circulating into the engine. Running the engine on gasoline is what causes the most damage. If you won’t be at the shop when the tow truck arrives, make a sign for the dash warning the shop owners not to start the engine!

What does gasoline do to a diesel vehicle?

Gasoline can damage the diesel fuel injection pump and the diesel fuel injectors in your car or truck. That’s because gasoline is less viscous that diesel and lacks the lubricating qualities. That lack of lubrication is what damages the pump and injectors.

In addition, gasoline can cause damage to the pistons and rods because gasoline has a much faster burn rate than diesel and builds pressure much faster.

What the shop will do to remove fix the problem

• Drain the entire fuel system – The shop must remove all traces of the contaminated diesel/gasoline mix from the fuel tank, fuel lines, filters, and pumps to avoid circulating the gasoline. They may have to drop the fuel tank itself in some cases.
• Flush the fuel system – The shop will flush the system using new diesel fuel. This may require repeat flushes to fully clean the injectors.
• Replace damaged parts – If gasoline entered the combustion chambers, injectors, pumps and other parts may require replacement due to internal damage.
• Change the oil – The shop will also change oil/lubricants contaminated by gasoline.
• Refill and test – Once the system is fully cleaned out and repaired, new ultra-low sulfur diesel is added and the vehicle is thoroughly tested before being released back to the owner.

How much does it cost to fix the problems created when you put gasoline in a diesel vehicle

If you drove the vehicle after filling it with gasoline, it’s not uncommon for a shop to spend at least a half full day labor to drop the tank and flushing all the lines, pump and injectors. That typically costs around $1,000 to $1,500. However, if the gasoline damaged parts, it’s very possible to see a repair bill close to $5,000

©, 2022 Rick Muscoplat