Shop Tries Everything to Kill 7.3L Power Stroke Diesel, But It Won’t Stay Dead

They filled the tank with everything but diesel, changed the oil with the engine running, and shot so much nitrous into the intake—but it hasn't quit yet.
Trying to kill a 7.3-liter Power Stroke
Smith's Diesel Performance via YouTube

People love a good underdog story. Whether we’re talking about the Rocky movies or David and Goliath, the built-in drama is enough to keep ’em hooked. And when you’re trying to destroy a 7.3-liter Ford Power Stroke diesel, guess which one you are? That’s right—you’re just like that boxer from Philly, or the shepherd boy from Bethlehem. But you can’t be sure your story will end the same way those did.

Smith’s Diesel Performance has an old Ford E-Series van that it apparently hates. I say that because they’ve been working for weeks to kill the dang thing. Running it on everything but diesel while also filling it with crappy oil still hasn’t been enough to do the job, though.

Now, these types of videos can get old quickly. You could argue that it’s a waste of a good engine, and I’d have to agree. But what’s impressive to me is just how stubborn the ol’ Power Stroke is. Makes me proud to own one, y’know?

In the shop’s first video, they filled the van’s fuel tank with 10 gallons of gasoline. It was already about half-full of diesel, however, so the 7.3-liter never even flinched. I’ve heard of lots of people running some gas in their diesel trucks to clean out the fuel system—just not this much. Still, it didn’t matter as the rig just kept running, and it wasn’t any more bothered when they poured a mix of used engine oil, differential oil, and transmission oil in the tank.

Their next attempt involved draining the truck’s sweet, thick engine oil and replacing it with a mix of O’Reilly brand 5W-20 and used 75W-90 diff oil. Normally, 10W-40 is the suggested lubricant for these power plants. I speak from experience when I say oil level and oil type most certainly matter on these 7.3-liters, not only because it keeps everything turning, but also because they use HEUI injection. That fuel delivery system shears oil, causing it to temporarily lose viscosity under high pressure (on purpose).

To make matters worse, they performed this oil change with the engine still running. And guess what? It didn’t matter. The van shut off for just a moment, but it started up again after and idled even more smoothly than before.

The most recent set of trials was clearly the worst. From performing a 20-second burnout while force-feeding it nitrous oxide, to spraying two cans of starting fluid into the intake and filling it with coolant, brake fluid, and butter—yup—the 7.3-liter stumbled significantly. It knocked, smoked, and became generally cranky. But still, with enough cetane booster, the engine was able to roar back to life.

Closing it all out was a test that involved running the van’s fuel tank almost dry and then dumping E85 into it. The sound was horrific, and it came incredibly close to dying for real as the engine eventually shut off. However, it was able to run again with used engine oil and cetane booster. You just can’t kill these things—at least, not with anything they’ve tried so far.

We Let Our Viewers Torture Our 7.3!!! Here’s What Happened... (Destroying The 7.3 Episode 3) thumbnail
We Let Our Viewers Torture Our 7.3!!! Here’s What Happened… (Destroying The 7.3 Episode 3)

I’m curious at this point to see what it’ll take to finally finish off the Power Stroke. They got the van for free, so they technically aren’t out any money if it bites the dust for good. It’s just hard to watch a seemingly good vehicle—albeit rusty—be run into the ground.

But as for the 7.3, well, it didn’t hear no bell.

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Caleb Jacobs

Senior Editor

From running point on new car launch coverage to editing long-form features and reviews, Caleb does some of everything at The Drive. And he really, really loves trucks.