My Wife Drove My Toyota Tacoma With 37K Miles and Accidentally Filled It Up With Diesel and It Wouldn’t Start, The Toyota Tech Saved My Truck and My Marriage

"My wife just filled my Toyota Tacoma with diesel fuel, and it won't start. Can you help me?"

That's the frantic call that Toyota technician mejicar (@menjicar) received from a 2022 Toyota Tacoma owner. You can imagine how upset the Tacoma owner was about the situation. 

Picture this: Your wife needs to drive your 2022 Toyota Tacoma pickup because her car is in the shop. You say, "Sure, but it's almost out of gas. Can you fill it up for me?" She says, "Sure, honey." But when she fills it up, she mistakenly fills it with diesel fuel instead of unleaded gasoline.  

It's a huge mistake because when she gets into the truck after paying at the pump, the truck won't start. She keeps trying, but the truck sputters once and then dies. The Tacoma is dead in the water.

You get the call that everyone dreads.

"Hi honey, I filled the Tacoma up, but now it won't start. The guy inside the store came out and told me I just put diesel fuel in it, not gasoline. Now it won't start."

You can imagine the thoughts going through his mind: How could you do that? I can't believe you filled it with diesel. Now my engine is ruined. But he holds his tongue and says, "Let me call my buddy and see if he can fix it." 

Your friend, who owns a car repair shop and is a Toyota Master tech, says, "Sure, get it towed in, and I'll look at it. I can get it fixed for you." You breathe a sigh of relief and call for a tow truck to pick it up at the gas station.

Toyota Master Tech mejicar says," So this guy's wife possibly damaged this truck. It's pretty sad, but this Toyota Tacoma with only 37,000 miles will not start." 

He cranks the engine over, but it's not starting. 

"Now I know exactly what it is. He told me that his wife filled the truck with diesel. 

The Master Tech says, "To verify it does have diesel in it, I'm going to spray some starting fluid into the manifold's throttle body. If the truck starts with the starting fluid, then I know it has diesel in it and it's not another issue. 

When he got back into the truck, its engine sputtered. Then, it started. It ran rough, but he quickly diagnosed the problem. 

Now, he must drain the diesel from the Tacoma's gas tank.

However, he shows viewers how easy it is. "We do that by disconnecting this fuel line that delivers gas into the engine. Now, I'll connect a rubber fuel hose to the metal fuel line, connect my OBD-II Scanner, and activate the fuel pump control." 

"I can check the remaining fuel volume and see that the tank is full. Now, I'll activate the truck's fuel pump and press high to pump the fuel out quickly."

He now pumps the diesel fuel from the truck into a storage tank. After that, he checks the gas gauge, which now shows empty with the low fuel light illuminated.

Now, he takes unleaded gas from a small tank and puts gasoline back into the Tacoma's gas tank. 

"Now it's time to see if the truck starts." He cranks the engine, and it sputters to life. The engine runs, and he shows smoke coming out the tailpipe as the engine burns up the remaining diesel fuel and gasoline mixture. 

He concludes, "Now that it's been running for a while, it's finally running smoothly again. Now I have to clear the warning codes from the engine, and it's done."

Now imagine the Toyota tech calling the Toyota Tacoma owner and saying, "Ok, man, your truck is fixed. You can pick it up anytime. I'm only charging you a couple of hours of labor, so it's all good."  

He says, "Oh, man, that's great. You just saved my truck and my marriage. Thanks a bunch!" 

It Happens More Often Than You Think

This Reddit post says, "I'm freaking out. I have a 2016 Chevy Silverado that my boyfriend put gasoline in today. It was on a quarter tank; he thought he'd be nice and fill it up for me. He gets home (drove 5 miles) and turns it off. I go out to start it, but it won't turn over. I've never had problems with this truck; it's never even hinted at not starting. I grill him. He admits he can't remember if he grabbed the green handle at the gas station. I smell the tank; it smells like diesel, not gas."

"Everything on the internet is either saying it will be fine if it's flushed and a new fuel pump and a few other parts OR the engine is destroyed, and I'll be out $25,000."

What Should You Do if You Accidentally Put Diesel In a Car or Truck?

Kelley Blue Book says, 

• Do not start the engine. It's crucial to keep the diesel in the tank and not let it into the fuel lines and cause damage.
• Do not panic. Mixing the two fuels is not, by itself, dangerous.
• Immediately call a dealership or local repair shop. Arrange for an emergency tow to get your vehicle to the service center.

"A mechanic will drain and rinse the gas tank to remove diesel and its residue. If you didn't start the engine, that's the only service necessary. However, additional work may be needed if you had driven with diesel in the gas tank. If you ran the engine until it stalled, technicians will likely:"

• Flush the fuel line. Typical cost: $200, depending on the vehicle and labor rates in your region.
• Service the fuel injector system. $250 for servicing, $1,200 or more if replacement is needed.
• Check the fuel pump for damage. $1,200 for replacement.
• Replace the fuel filter. $200 for replacement.
• Replace spark plugs. $100 for replacement.

Tips to Avoid Getting Diesel Into a Gas Engine

KBB says, "Incidents of diesel entering car gas tanks are infrequent but not unheard of. To avoid mistakenly getting diesel fuel in your gas car, pay attention at the pump and don't pick up handles with a "Diesel" label."

• Diesel pumps typically have green handles that give you another visual clue of the fuel type.
• The nozzle on a diesel pump has a larger diameter than its gasoline counterparts to prevent it from being inserted into a gas tank's opening.
• Diesel smells like kerosene, while gasoline smells more like paint thinner.

Final Thoughts and Questions For Toyota Tacoma Owners

The Master Toyota tech did a good job of getting this Toyota Tacoma running with minimal time and cost. However, he should have replaced the fuel filter after completing the job. 

How About You?

Have you ever put diesel into your vehicle by mistake? How did you get it fixed? If so, click the red Add New Comment link below and let us know.

Check out my Toyota Tacoma report titled; 2024 Toyota Tacoma Owner Says, “I Change the Oil In My Tacoma Every 3,500 Miles, I Don’t Care That Toyota Says Change It Every 10,000 Miles”

I am Denis Flierl, a Senior Torque News Reporter since 2012. My 30+ year tenure in the automotive industry, initially in a consulting role with every major car brand and later as a freelance journalist test-driving new vehicles, has equipped me with a wealth of knowledge. I specialize in reporting the latest automotive news and providing expert analysis on Subaru, which you'll find here, ensuring that you, as a reader, are always well-informed and up-to-date. Follow me on my X SubaruReport, All Subaru, WRXSTI, @DenisFlierl, Facebook, and Instagram.

Photo credit: Denis Flierl