The 2002 Expedition is a body-on-frame workhorse that suffers from critical engine failures on the 5.4L Triton and transmission cooling issues that can destroy the 4R100 automatic. These aren't just maintenance items—they're platform-defining catastrophic failures that hit without warning.
5.4L Triton Spark Plug Ejection and Cam Phaser Failure
Common · high severityTypical onset: 80,000-150,000 mi
Symptoms: Spark plug blows out of cylinder head under load or acceleration, Loud rattling/knocking on cold start that quiets after warmup (cam phasers), Check engine light with misfire codes (P0301-P0308), Sudden loss of power and rough running
Fix: Spark plug ejection requires thread repair inserts (Time-Sert or HeliCoil), typically 3-5 hours per cylinder if caught early. If the head is damaged, you're looking at removal and machine work (12-16 hours). Cam phaser replacement requires timing chain work on both banks, 10-14 hours labor. Many shops recommend doing both phasers, chains, and guides as a package.
Estimated cost: $800-1,500 per ejected plug, $2,000-3,500 for cam phaser job
Internal Transmission Oil Cooler Failure (Strawberry Milkshake of Death)
Common · high severityTypical onset: 100,000-180,000 mi
Symptoms: Pink or strawberry-colored transmission fluid (coolant mixing), Transmission slipping, delayed engagement, or no movement, Engine overheating due to ATF contaminating cooling system, Coolant level drops with no visible external leaks
Fix: The radiator's internal ATF cooler fails and mixes coolant into the transmission, destroying it within miles. Requires radiator replacement, transmission flush or rebuild (usually rebuild by the time it's caught), and complete cooling system flush. External ATF cooler installation is mandatory to prevent recurrence. Total 14-20 hours if transmission needs rebuild.
Estimated cost: $3,000-5,500 with transmission rebuild
Intake Manifold Gasket/Coolant Crossover Leaks
Common · medium severityTypical onset: 70,000-120,000 mi
Symptoms: Coolant weeping from rear of intake manifold, Sweet coolant smell in cabin or under hood, Gradual coolant loss without visible external puddles, White smoke from exhaust on cold start (if internal leak develops)
Fix: Plastic coolant crossover passages crack and intake manifold gaskets fail on both the 4.6L and 5.4L. Requires removing upper intake plenum to access. While you're in there, replace the thermostat and upper radiator hose. 5-7 hours labor for thorough job.
Estimated cost: $800-1,400
Front Hub Bearing and Ball Joint Failures
Common · medium severityTypical onset: 80,000-130,000 mi
Symptoms: Grinding or humming noise that increases with speed, Clunking over bumps or when turning, Loose or wandering steering feel, Vibration through steering wheel
Fix: The independent front suspension wears wheel bearings and upper/lower ball joints aggressively, especially with heavy loads or trailer towing. Bearings are hub assemblies (2-3 hours per side). Ball joints require pressing or replacing entire control arms. Budget for doing both sides and an alignment. Each corner is 3-4 hours.
Estimated cost: $600-900 per wheel bearing, $800-1,200 per side for ball joints
Rear Differential Pinion Seal and Bearing Failure
Occasional · medium severityTypical onset: 90,000-150,000 mi
Symptoms: Gear oil dripping from front of rear differential, Howling or whining noise from rear end that changes with speed, Clunking when shifting from drive to reverse, Low gear oil level found during inspection
Fix: Pinion seal leaks are common and if ignored, lead to bearing failure. Seal replacement alone is 2-3 hours. If the pinion bearing is already noisy, you're into a full differential rebuild or replacement (8-12 hours). Replace the cover gasket while you're there.
Estimated cost: $400-700 for seal, $1,500-2,500 for bearing/rebuild
Fuel Pump Driver Module Failure
Occasional · high severityTypical onset: 60,000-140,000 mi
Symptoms: No start or intermittent stalling, especially when hot, Engine cranks but won't fire, Fuel pump doesn't prime when key is turned on (no hum), Starts after sitting and cooling down
Fix: The fuel pump driver module (FPDM) mounts on the frame rail and fails due to heat and corrosion. Common no-start culprit that mimics fuel pump failure. Module replacement is straightforward, 1-1.5 hours, but misdiagnosis often leads to unnecessary fuel pump replacement first.
Estimated cost: $300-500
Rear HVAC Blower Motor and Resistor Failure
Occasional · low severitySymptoms: Rear A/C or heat stops blowing air, Only works on highest speed setting, Squealing or grinding noise from rear ceiling area, Intermittent operation
Fix: Rear climate blower motor and resistor fail independently. Resistor is easier (1 hour), motor requires headliner removal or access through rear cargo area (2-3 hours depending on trim level). Not safety-critical but miserable for rear passengers in summer.
Estimated cost: $250-450 for resistor, $400-700 for motor
Buy only if you find a well-maintained 4.6L example with service records and budget $3,000-5,000 for inevitable repairs—the 5.4L is a gamble not worth taking at this age.
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.