6.4 Fords… are they really that bad?

I drive a work truck with a 6.4… when it’s not in the shop. It spends more time being repaired than on the road.

It’s good for about 10,000 miles before issues start.

This one just had one of the turbos and injectors replaced.

I’ve worked on a lot of them. They can last if they’re well-maintained and not tuned too aggressively. But they’re a pain to work on—turbo removal with the cab on is awful, and oil coolers are worse. 6.4s are meant to be worked on with the cab off. I only buy 7.3s or 5.9 Cummins, for what it’s worth.

I’ve had 7.3s, but I just got a 5.9 Cummins and love it. No idea why I waited so long.

Same here. The 5.9 is so much easier to work on and drive. I upgraded my transmission with billet parts and an upgraded valve body. It’s a dream compared to the 7.3, but I do miss the space in my Ford.

I upgraded the valve body and governor solenoids on mine too. Now I’m planning a G56 manual swap. Didn’t want another manual, but it’ll be worth it in the long run.

Go for a 7.3. Mine has 480,000 miles and still runs strong.

6.0s, when done right, can be reliable if the owner doesn’t cut corners. I have three and love them.

6.4s… I want to love them. They’re fast and powerful, but they die the same way every time—cracked pistons. I just bought a 2010 F250 with no engine because the #8 piston melted. Whatever you do, don’t buy a 6.4. They’re the true boat anchors of today’s diesels.

There’s a reason it was only made for three years.

Diesel World has a great breakdown of all the issues: Why the 6.4L is so awful.

They’re about as useful as eating pickle juice with a fork.

Edit: I’m shocked it lasted this long. Run.

I loved mine. It was fast, torquey, and got 20+ MPG if I drove it easy. Bought it at 98k miles for $21k and sold it at 137k miles for $18k. Six months after I sold it, a piston cracked at 150k and totaled it.

I’m on my second 6.4 now. My current one is at 205k miles and was bulletproofed at 175k. I love the power and comfort, but I’m saving up for a full rebuild when it eventually goes.

Stock, they’re terrible. Deleted and tuned, they’re decent. Built, tuned, and deleted? They’re great.

I bought it. Where’s the best place to get the deletes? My last truck was a 2012 Dodge, and I used an H&S tuner and a Sinister EGR delete.

Delete it, but don’t push it too hard unless you upgrade the block and pistons. Most issues with the 6.4 come from the emissions systems, but it depends on what your long-term plans are.

I’ll trade it in after three years and get a Dodge with a manual. I just want decent MPG and for it not to blow up in the meantime.