The 2017 Ford Expedition still uses the older 5.4L Triton 3-valve V8 (final year before the refresh), carrying forward decade-old engine and transmission issues. This platform is known for catastrophic cam phaser failure, spark plug ejection, and transmission cooler line leaks — the repair data showing engine rebuilds and short blocks tells the story.
Cam Phaser Failure & Timing Chain Rattle
Common · high severityTypical onset: 80,000-150,000 mi
Symptoms: Cold-start rattle that lasts 5-30 seconds then quiets, Check engine light with cam position codes (P0012, P0022), Loss of power on acceleration, Eventually progresses to constant rattle and won't pass emissions
Fix: Requires timing chain job with phaser replacement — both sides if doing it right. 12-16 labor hours because you're pulling the front of the engine. Many shops replace chains, guides, tensioners, and both phasers as an assembly. This is the most common reason these engines get pulled or traded in.
Estimated cost: $2,800-4,500
Spark Plug Ejection (Threads Strip from Head)
Occasional · high severityTypical onset: 60,000-120,000 mi
Symptoms: Sudden misfire with loud pop or hissing sound, Check engine light with misfire codes, Loss of power, runs on 7 cylinders, Plug literally blows out of cylinder head during acceleration
Fix: The 3-valve Triton heads have inadequate thread engagement — plugs can blow out and strip threads. Repair requires HeliCoil or TimeSert thread insert if caught early (2-3 hours), but often damages coil and surrounding area. If head is cracked or severely damaged, you're looking at head removal and possible replacement (8-12 hours per side). Prevention: never overtorque plugs, use anti-seize, replace at 60k with Motorcraft parts only.
Estimated cost: $400-800 for insert, $2,500-4,000 if head work needed
Transmission Oil Cooler Line Failure
Common · high severityTypical onset: 70,000-130,000 mi
Symptoms: Pink or red fluid puddle under vehicle (mixing ATF and coolant), Transmission overheating warning, Milky/strawberry-colored fluid in coolant reservoir, Harsh shifting or slipping after contamination starts
Fix: The cooler lines corrode and fail where they connect to the radiator, causing coolant and ATF to mix — this kills the transmission fast. Fix requires new cooler lines, radiator flush, and transmission flush minimum (4-6 hours). If coolant got into trans, you're looking at a rebuild or replacement. Catch it early or you're buying a transmission.
Estimated cost: $600-1,200 if caught early, $3,500-5,500 if transmission contaminated
Intake Manifold Runner Control Failure
Occasional · medium severityTypical onset: 90,000-140,000 mi
Symptoms: Check engine light with P2004-P2008 codes, Rough idle, especially when cold, Poor fuel economy, Lack of power at low RPM
Fix: The IMRC actuators and flap linkages stick or break due to carbon buildup and plastic deterioration. Requires intake manifold removal to access and replace actuators/solenoids (5-7 hours). Sometimes you can clean them, but replacement is more reliable long-term.
Estimated cost: $800-1,400
Power Brake Booster Vacuum Leak
Occasional · high severityTypical onset: 100,000-160,000 mi
Symptoms: Hard brake pedal, requires excessive force to stop, Hissing sound when pressing brake pedal, Engine runs rough at idle with brakes applied, Check engine light with lean codes (P0171/P0174)
Fix: The brake booster diaphragm fails and creates a massive vacuum leak. Replacement is straightforward but labor-intensive due to tight firewall access (3-5 hours). There was a recall for some units, but many fail outside recall scope. This is a safety issue — don't drive it hard-pedal.
Estimated cost: $600-1,000
Rear HVAC Blower Motor Failure
Common · low severityTypical onset: 80,000-120,000 mi
Symptoms: Rear climate control stops blowing air, Squealing or grinding noise from rear HVAC, Rear passengers get no heat or AC, Front HVAC works fine
Fix: The rear auxiliary blower motor bearings fail or the resistor burns out. Access requires removing right rear quarter trim panel — awkward but not terrible (2-3 hours). Common enough that some shops keep these motors in stock. Related to a recall for some units with potential fire risk.
Estimated cost: $400-700
Hard pass unless under 60k miles with impeccable service records — the 5.4L 3V is at the end of its service life by 2017, and you're inheriting 10+ years of known design flaws with expensive consequences; the 2018+ 3.5L EcoBoost is a vastly better platform.
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.