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2008 Ford F-350 Super Duty (6.4L Power Stroke) — Should You Buy One?

Typical asking price: $12,000–$24,000. There are 4 high-severity known issues you need to know before handing over a check.

Kestrel Take

Ford's answer to the 6.0 was an engine that fixed the head gaskets and introduced a fuel dilution problem and a $6,000 turbo. It makes great power and it is thirsty, complicated, and expensive. The 6.4 is a truck for people who enjoy owning a project.

Known Issues for the 2008 Ford F-350 Super Duty (6.4L Power Stroke)

Ranked by wallet impact. These are documented, recurring problems — not freak accidents.

Fuel dilution of engine oil from in-cylinder regenerationHigh — wallet impact

The DPF regeneration strategy injects fuel late in the cycle, which washes into the crankcase. Oil level rises, viscosity collapses, and bearings suffer. Short-trip trucks are the worst affected.

Repair cost range: Engine damage, $8,000-$15,000

Compound turbocharger failureHigh — wallet impact

The two-stage turbo system is expensive and fails from soot and heat. Replacement is a major job.

Repair cost range: $3,000-$6,000

Radiator and EGR cooler failuresHigh — wallet impact

Both crack and leak. The radiator is a known weak point and the job is labor-intensive.

Repair cost range: $1,200-$3,000

Piston and connecting rod failure at high powerHigh — wallet impact

Tuned 6.4s crack pistons. Any evidence of a performance tune should be treated as a major risk.

Repair cost range: $10,000-$18,000

Fuel economyMedium

11-13 mpg unloaded is normal. This is a genuine ownership cost, not a defect.

Repair cost range: n/a

Walk-Away Red Flags

  • Oil level above full with a fuel smell
  • Any performance tune or deleted emissions with no documentation
  • Short-trip city use history on a DPF diesel
  • Coolant loss

Good Signs

  • Highway and towing use — exactly what this engine wants
  • Frequent oil changes with documented oil analysis
  • Turbos and radiator already replaced

Found a specific Ford F-350 Super Duty (6.4L Power Stroke)?

This page covers what goes wrong on the 2008 Ford F-350 Super Duty (6.4L Power Stroke) in general. The Kestrel report covers this specific car— the asking price vs. market, the photos, the seller's description, and a BUY / NEGOTIATE / WALK AWAY verdict with a negotiation script.

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Known issues on this page are based on documented owner reports, NHTSA complaints, class-action records, and manufacturer technical service bulletins. Individual vehicles vary. A pre-purchase inspection by a trusted mechanic is always worth doing.