The 2020 F-350 Super Duty represents the tail end of the third-gen platform before the 2023 redesign. The 6.7L Power Stroke is generally solid but has specific failure points around emissions and cooling; the 7.3L Godzilla gas engine has proven bulletproof but thirsty.
6.7L Power Stroke CP4 Fuel Pump Failure
Occasional · high severityTypical onset: 80,000-150,000 mi
Symptoms: Sudden loss of power, rough running, or complete no-start, Metal contamination throughout entire fuel system when pump grenades, Fuel in oil (dilution) as early warning sign
Fix: Complete fuel system flush required: injectors, lines, tank cleaning, new CP4 pump replacement. 18-24 labor hours for full remediation. This is catastrophic when it happens — metal shavings destroy injectors and contaminate everything downstream.
Estimated cost: $8,000-12,000
6.7L Power Stroke EGR Cooler Failure and Coolant Loss
Common · high severityTypical onset: 60,000-120,000 mi
Symptoms: White smoke from exhaust on cold start, Coolant loss with no visible external leaks, Rough idle, extended cranking when hot, P0401 or P0402 EGR codes
Fix: EGR cooler replacement involves cab removal for proper access on these chassis. 16-20 hours labor. Often discover intake manifold gasket and oil cooler issues during this job, so budget for additional work. Coolant enters combustion chamber through cracked cooler.
Estimated cost: $4,500-6,500
10R140 Transmission Oil Cooler Line Leaks
Common · medium severitySymptoms: Transmission fluid pooling under truck, often passenger-side frame rail, Low fluid level causing delayed engagement or slipping, Fluid visible on crossmember or running down frame
Fix: Factory cooler lines and connections at radiator are known weak points. Lines corrode or fittings crack at crimp points. Replace lines and often the in-radiator cooler section. 4-6 hours labor depending on configuration and access.
Estimated cost: $800-1,400
6.7L Power Stroke Turbo Actuator and VGT System Issues
Occasional · medium severityTypical onset: 70,000-130,000 mi
Symptoms: Limp mode with P0299 underboost or P003A overboost codes, Poor throttle response, lack of power under load, Whistling or surging on acceleration, Turbo vanes sticking (carbon buildup)
Fix: Turbo actuator replacement or full turbo rebuild if vanes are seized. Carbon cleaning of VGT mechanism sometimes buys time. 6-8 hours for actuator, 10-14 for turbo R&R. Catch early or risk complete turbo failure.
Estimated cost: $1,200-3,800
Front Seat Recliner Mechanism Failure (NHTSA Recall)
Occasional · high severitySymptoms: Driver or passenger seat back suddenly reclines without input, Recliner handle feels loose or ineffective, Seat back won't lock in position
Fix: Covered under NHTSA recall 20V-636. Seat recliner mechanism replacement, typically 2-3 hours per seat at dealer. Safety issue — seat can collapse rearward in crash or hard braking. Check recall status before purchase.
Estimated cost: $0 (recall)
6.7L Power Stroke Diesel Particulate Filter (DPF) Clogging and Regen Issues
Common · medium severityTypical onset: 50,000-100,000 mi
Symptoms: Frequent active regen cycles (noticeable fuel smell, higher idle), Reduced power, derate events with DPF differential pressure codes, Check engine light with P2002 or P244B codes, Poor fuel economy
Fix: DPF cleaning or replacement if too far gone. Short-trip driving accelerates clogging. DPF service (bake/clean) runs 4-6 hours; full replacement 8-10 hours. Many owners face this if truck never sees highway miles for proper passive regen.
Estimated cost: $600-1,200 (cleaning) or $3,500-5,000 (replacement)
Dana M275 Rear Axle Seal Leaks (Super Duty Specific)
Occasional · low severityTypical onset: 40,000-80,000 mi
Symptoms: Gear oil on inside of rear wheel or diff cover, Visible drips from pinion seal or axle tube seals, Low differential fluid level on inspection
Fix: Pinion seal or axle shaft seals replacement. Common on work trucks that see towing or heavy loads. 2-4 hours depending on which seal. Catch early to avoid bearing damage from low fluid.
Estimated cost: $400-800
Buy the 7.3L gas if you can stomach 10 MPG — dead reliable. Diesel is capable but expect $5-8k in emissions/fuel system work over 150k miles; still worth it for serious towing, just budget accordingly.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.