The 2017 F-350 with the 6.7L Power Stroke is a workhorse that generally holds up well under heavy use, but certain CP4 fuel system failures and emissions components can cause catastrophic damage and expensive repairs. Most issues are preventable with proper maintenance, but when they go wrong, they go expensive.
CP4.2 High-Pressure Fuel Pump Failure (Catastrophic)
Occasional · high severityTypical onset: 60,000-150,000 mi
Symptoms: Sudden loss of power and rough running, Metal shavings in fuel system, Long crank or no-start condition, Fuel in oil (dilution), Complete engine failure if metal circulates
Fix: When the CP4 pump fails, metal contamination spreads through the entire fuel system requiring replacement of injectors, fuel rails, fuel lines, tank cleaning, and sometimes complete engine rebuild if metal reached cylinders. 40-80 labor hours depending on contamination extent. This is THE nightmare scenario for 6.7L owners.
Estimated cost: $8,000-25,000
EGR Cooler Failure and Clogging
Common · medium severityTypical onset: 80,000-130,000 mi
Symptoms: White smoke from exhaust, Coolant loss with no visible leaks, Overheating under load, Rough idle and reduced power, Check engine light with EGR codes (P0401, P0402)
Fix: EGR cooler develops leaks or carbon buildup restricts flow. Requires cooler replacement and full EGR system cleaning. Often do EGR valve and sensors at same time. 8-12 hours labor. Use Motorcraft parts, aftermarket coolers often fail quickly.
Estimated cost: $2,200-3,800
Turbocharger Wastegate Actuator and Vane Sticking
Common · medium severityTypical onset: 100,000-180,000 mi
Symptoms: Lack of boost and power under acceleration, Black smoke on heavy throttle, Overboost codes (P0234, P003A), Turbo whine or whistle changes, Limp mode activation
Fix: Variable vane turbos on these engines stick from carbon buildup or actuator fails. Can sometimes clean vanes with turbo off (12-14 hours), but usually requires turbo replacement or rebuild. Catch it early before bearing damage. Delete kits exist but aren't emissions legal.
Estimated cost: $2,500-4,500
Diesel Exhaust Fluid (DEF) System Failures
Common · medium severityTypical onset: 70,000-120,000 mi
Symptoms: DEF quality poor warning, Speed limited to 55 mph after countdown, Check engine light with NOx sensor codes, DEF pump not priming, DEF freezing issues in extreme cold despite heater
Fix: DEF pumps, heaters, and NOx sensors fail regularly. Pump replacement requires dropping DEF tank (6-8 hours). NOx sensors run $300-600 each and there are two. Always use quality DEF, dollar-store DEF crystalizes and kills components. Ford extended warranty on some DEF components to 10yr/120k.
Estimated cost: $1,200-3,000
Transmission Oil Cooler Line Leaks
Occasional · medium severityTypical onset: 60,000-100,000 mi
Symptoms: Transmission fluid puddles under truck, Fluid level drops between services, Burnt transmission smell, Hard shifts when fluid gets low, Pink residue on cooler lines or radiator
Fix: Factory quick-connect fittings on transmission cooler lines crack and leak, especially on plow trucks or those seeing road salt. Replace lines with heavy-duty aftermarket or full hard-line kit. 3-5 hours labor. Catch early before transmission damage from low fluid.
Estimated cost: $600-1,200
Radiator and CAC (Charge Air Cooler) Leaks
Occasional · medium severityTypical onset: 90,000-140,000 mi
Symptoms: Coolant loss requiring frequent top-offs, White residue on front of radiator/CAC stack, Overheating in hot weather or towing, Loss of boost pressure (CAC leak), Sweet coolant smell from front of truck
Fix: Plastic end tanks crack on radiators and CAC units, rock damage common on grille-mounted CAC. Requires removing entire cooling stack (bumper off). 6-10 hours labor depending on what needs replacement. Upgrade to all-aluminum units if budget allows.
Estimated cost: $1,800-3,500
Door Latch Failures (Safety Recall 17V-400)
Occasional · high severitySymptoms: Door will not close properly, Door appears closed but pops open, Door ajar warning stays on, Door opens while driving, Latch makes clicking noise but doesn't engage
Fix: Pawl spring in door latch fails causing doors to unlatch unexpectedly. Ford issued recall 17V-400 for this. Free repair at dealer involves latch replacement. Takes 1-2 hours per door. Get this done immediately for safety—doors opening at highway speed is life-threatening.
Estimated cost: $0 (recall)
Solid heavy-duty platform if maintained properly and the CP4 pump hasn't grenaded, but that fuel pump is a ticking time bomb—budget $1,500 for prevention kit or walk away from high-mileage examples without service records.
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.