A mechanic on TikTok just showed why you should double-check what fuel you’re pumping—especially if you’re not used to the car.
In his recent video, which has garnered over 407,400 views at the time of writing, TikTok creator and auto technician @menjicar, walks viewers through a truck that wouldn’t start.
The reason? Someone accidentally filled it with diesel instead of gasoline.
A simple mistake that shut the Toyota Tacoma down
“This guy’s wife possibly damaged this guy’s truck,” he says at the start of the video.
The truck in question is a Toyota Tacoma with only 37,000 miles on it. It should be running fine, but it won’t start.
“I know exactly what it is,” @menjicar says. “The dude told me that his wife put diesel inside the truck.”
To confirm, he sprays starting fluid into the throttle body and cranks the engine.
“If the truck does start with the starting fluid, we know it’s a fueling issue,” he explains.
Sure enough, the truck turns over—but runs “really rough” as it burns out whatever fuel is still inside. That’s enough proof to show the technician the tank is filled with diesel.
Draining the wrong fuel
Fixing the issue means draining the entire tank, according to the technician.
“Now the way we do that is disconnecting one of these fuel lines,” he explains. “These fuel lines bring fuel into the engine, and the other one takes the remaining fuel back into the fuel tank.”
After disconnecting a fuel line, he confirms that the smell of diesel is strong. From there, he uses a rubber hose to help pump the fuel out.
With the help of a scan tool, he monitors the fuel levels, showing 77% of the tank is still full. Selecting the high-pump setting, he starts draining.
“So the fuel line is connected and sure enough, anybody want 14 gallons of diesel?” he jokes.
Eventually, the fuel level drops to just 6%, then nearly empty. Once the tank is dry, it’s time to refill it with fresh gas and see if the truck will start.
Will it start?
After filling up with the right fuel, @menjicar cranks the truck. It struggles at first but then fires up.
“All right, so after a while being on, this thing finally turns on decently,” he says.
Now all that’s left is to clear the misfire codes that popped up from the diesel mistake.
What happens if you put diesel in a gas car?
While diesel and gasoline might seem interchangeable, putting diesel in a gas-powered vehicle can cause serious problems.
According to Kelley Blue Book, gasoline engines rely on spark plugs to ignite the fuel, while diesel engines use compression. Another difference is that diesel fuel is thicker and burns differently, which means a gas engine won’t be able to process it properly.
If you accidentally put diesel in your gas car, Top Driver advises not starting the engine. Instead, they suggest getting the vehicle towed and having the tank drained immediately to prevent further damage.
Commenters share their thoughts
In the comments, users debated the severity of the mistake, with some saying diesel in a gas engine isn’t as bad as the other way around, while others questioned how it happened in the first place.
“diesel in a petrol isn’t to bad. but petrol in a diesel is party over for the engine,” stated one user.
“Aren’t the diesel nozzles supposed to be bigger so they don’t fit in gas vehicles?!” asked another. This is in fact true, but it isn’t a universal standard, and mistakes can still happen.
“why would u run it or even try starting it if u know it gas deisel, just gon make it worse,” asked a third, to which the mechanic responded, “Verifying concern.”
The Daily Dot has reached out to Toyota and Menjicar via email for comments.
@menjicar Guy came in because his wife accidentally put diesel into his new Toyota truck. Luckily the truck cleared up after a while and was back to normal. Goes to show how good Toyotas are. #toyota #mywife #marriedlife #imjustagirl #automotive #bestmechanic #autotech #shadymechanic #automotivetechnician #toyotatacoma ♬ original sound – Menjicar
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