2021 FORD F-350

Typical onset: 30,000-80,000 mi

Symptoms: Sudden onset knocking or slapping noise from bottom end, Metal shavings in oil filter, Loss of power, Check engine light with misfire codes, Catastrophic failure can occur without warning

Fix: Complete engine teardown required, typically replacing all pistons, wrist pins, and inspecting/replacing connecting rods and bearings. Some cases require full short block. 25-35 labor hours depending on cab-on or cab-off approach. Ford extended warranty coverage through 2023 for some VINs.

Estimated cost: $15,000-25,000

Typical onset: 40,000-90,000 mi

Symptoms: Transmission fluid weeping or spraying from cooler lines at radiator, Low trans fluid warning, Burnt transmission fluid smell, Slipping or delayed engagement if fluid level drops significantly

Fix: Replace cooler lines and fittings at radiator, flush contaminated coolant if cross-contamination occurred. Common on trucks with frequent towing. 3-5 labor hours including system flush and refill.

Estimated cost: $800-1,500

Typical onset: 50,000-100,000 mi

Symptoms: Clunking when shifting from park to drive or reverse, Vibration through cab at idle in gear, Excessive drivetrain movement visible under throttle application, Binding sensation during shifts

Fix: Replace rear transmission mount (crossmember mount), inspect front support. Especially common on diesel models with high torque and towing duty. 2-3 labor hours.

Estimated cost: $400-700

Symptoms: Hard starting when cold, Loss of power under load, Rough idle, Extended cranking, P0093 or P0088 fuel pressure codes

Fix: Premature fuel filter clogging traced to fuel tank debris and poor fuel quality. Requires fuel filter replacement, sometimes fuel tank drop and cleaning if debris source identified. Some cases need injector cleaning or replacement. 2-8 hours depending on scope.

Estimated cost: $300-3,000

Typical onset: 80,000-150,000 mi

Symptoms: Reduced power, High exhaust gas temperatures, P0401 or P0402 EGR flow codes, White smoke on cold start, Coolant loss without external leaks

Fix: EGR cooler becomes clogged with soot or develops internal coolant leaks. Requires EGR cooler replacement and system cleaning. 8-12 labor hours cab-on, less if cab pulled. More common with short-trip duty cycles.

Estimated cost: $2,500-4,500

Typical onset: 60,000-120,000 mi

Symptoms: Sudden misfire on one cylinder, Hissing or ticking noise from cylinder head, Loss of compression on affected cylinder, Check engine light with misfire code

Fix: Aluminum head spark plug threads can strip or allow plug ejection, similar to older Ford modular engines but less frequent. Requires HeliCoil or TimeSert thread repair. 2-4 hours per cylinder.

Estimated cost: $500-900