See How Surprisingly Clean This 700,000-Mile 7.3 Power Stroke Diesel Engine Is Inside
The almighty 7.3L has a legendary reputation for reliability, and a look inside this high-mileage lump shows why.
The 7.3-liter Power Stroke is the measuring stick for every other Ford diesel, at least in terms of reliability. It's so legendarily tough that even Duramax and Cummins drivers tip their Hooey hats toward them, usually while giving the backhanded compliment that they're too underpowered to break anything. That may be true, but a look inside this believed 700,000-mile engine ought to be enough proof for anyone who doubts its hard-earned rep.
It's important to note that there's some debate over the true mileage of this engine. It was pulled from a truck whose odometer displayed 699,341 miles, and while discrepancies on the CarFax showed the truck hopping from 68,372 miles to nearly 686,000 miles in just two months, the clearest signs point toward it being a legitimately high-mile lump. You'll see why in time, but let's get this show on the road.
Eric, the guy behind the I Do Cars YouTube channel, makes a living by parting out junkyard cars and trucks, so he's gone through the teardown process plenty of times before. Starting with the accessories and components that are mounted atop the engine, he gets stuck on the turbo for a minute but eventually breaks it loose. It looks to be a factory-style Garrett charger that was replaced around 2004 according to a date tag, lending further credence to the idea that this truck racked up lots of miles in a hurry.
Unsurprisingly, the water pump looks rough on the inside, and it was even cracked in the collision that totaled the truck. There are grooves in the housing where the impeller hit it repeatedly for miles on end. This isn't exactly uncommon and, for what it's worth, it worked right up until the wreck.
Removing the valve cover revealed a clean head with paint markings still on the valve springs. The injectors proved to be a challenge—Eric broke two in the process—and while they appear to be clean, at least four of them were clearly stamped as remanufactured, so there's not much point in evaluating their condition without also knowing the date. The rockers and pushrods are nearly immaculate, though, and the valvetrain as a whole looks like it's in exceptional shape. There's carbon buildup, but that'd probably be there in an engine with less than half the miles.
Most of the noteworthy discoveries came after finally lifting the 113-pound head off the block with a forklift. Peeking inside the cylinders showed clean crosshatchings throughout, albeit with visible rings around the top of each. One piston is cracked, possibly from the impact due to the cylinder's location on the edge of the block, and just about every main bearing was worn down to the copper.
Significant wear on the camshaft indicates that this is likely a 700,000-mile engine as advertised. The same can be said for the crankshaft, which has pitting on almost every journal. Keep in mind that the truck still ran with all these issues, so even though it's not sparkling clean, it chugged along regardless.
If you've got nearly an hour to kill, you can watch the entire teardown video. Eric does a good job walking through it all, and he's honest about the engine's history being questionable at best. It was built and driven during the 2000s when CarFax records weren't always well-kept, so that's just the way it is. Still, I'd bet that this power plant has seen more miles than anything I've driven.
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