The 2015 Explorer suffers from catastrophic engine failures on both powertrains, with the 3.5L EcoBoost being particularly notorious for carbon buildup and coolant intrusion issues, while transmission cooling system failures plague both engine options and lead to expensive transmission damage if not caught early.
3.5L EcoBoost Catastrophic Engine Failure (Carbon Buildup & Coolant Intrusion)
Common · high severityTypical onset: 80,000-120,000 mi
Symptoms: White smoke from exhaust on cold starts, Coolant loss with no visible leaks, Misfires and rough idle, Sudden loss of power, Knocking sounds from engine, Check engine light with misfire codes
Fix: Direct injection carbon buildup causes valve sticking, while factory PTU/water pump coolant leaks can seep into cylinders through intake manifold. Complete engine rebuild or replacement required once internal damage occurs. 25-35 labor hours for long block replacement, 40+ hours for full rebuild with heads, pistons, bearings.
Estimated cost: $8,000-15,000
Transmission Oil Cooler Failure and Trans Contamination
Common · high severityTypical onset: 60,000-100,000 mi
Symptoms: Transmission slipping or harsh shifting, Coolant in transmission fluid (strawberry milkshake appearance), Transmission overheating warnings, Engine overheating, Loss of gears or limp mode
Fix: Internal transmission cooler inside radiator fails, allowing coolant and trans fluid to mix. Requires radiator replacement, complete transmission flush or rebuild, and all cooling system lines cleaned. If caught early (just cooler), 4-6 hours. If trans damaged, add 15-20 hours for rebuild.
Estimated cost: $800-1,200 (cooler only), $3,500-5,500 (with trans rebuild)
2.0L EcoBoost Engine Failure (Piston Ring and Bearing Failure)
Occasional · high severityTypical onset: 70,000-110,000 mi
Symptoms: Excessive oil consumption (quart every 500-1000 miles), Blue smoke from exhaust, Metallic knocking or rattling, Loss of compression, Rod knock at idle, Low oil pressure warning
Fix: Piston ring land failures and connecting rod bearing wear lead to complete engine failure. Often requires short block or complete engine replacement. Some cases covered under Ford's extended warranty up to 150k miles. 20-30 hours labor for engine replacement.
Estimated cost: $6,000-10,000
Rear Suspension Lower Control Arm and Toe Link Fractures
Common · high severityTypical onset: 50,000-90,000 mi
Symptoms: Clunking from rear suspension over bumps, Vehicle pulling to one side, Uneven rear tire wear, Rear end feeling loose or unstable, Visible cracks in control arms during inspection
Fix: Factory rear lower control arms and toe links fracture due to poor welds and metal fatigue, covered under multiple recalls but still occurring. Replace all four rear lower control arms and inspect toe links. Requires alignment. 3-4 hours labor per side if doing preventively.
Estimated cost: $800-1,500
Power Transfer Unit (PTU) Seal Leaks and Fluid Starvation
Common · medium severityTypical onset: 40,000-80,000 mi
Symptoms: Fluid puddles under front of vehicle (passenger side), Whining or grinding noise from front differential area, Vibration during acceleration, Burning smell, AWD malfunction warning
Fix: PTU seal fails, leaks fluid, and Ford's service intervals (never) mean most run dry and fail. Requires PTU seal replacement or complete PTU unit if damaged. Preventive fluid changes every 30k miles essential. 2-3 hours for seal, 4-5 hours for PTU replacement.
Estimated cost: $400-800 (seal), $1,500-2,500 (PTU replacement)
Transmission Mount Failure
Common · low severityTypical onset: 60,000-100,000 mi
Symptoms: Clunk when shifting from park to drive or reverse, Excessive vibration at idle, Thud during hard acceleration, Visible transmission movement
Fix: Hydraulic transmission mount fails due to fluid leak inside the mount. Simple replacement but affects drive quality significantly. 1.5-2 hours labor.
Estimated cost: $300-500
Backup Camera Failure and Liftgate Water Intrusion
Occasional · low severitySymptoms: Backup camera showing black screen or distorted image, Intermittent camera operation, Water visible inside liftgate camera housing, Electrical issues with liftgate
Fix: Camera seals fail allowing water intrusion. Covered under recall for some VINs. Replace camera and reseal liftgate harness entry point. 1-2 hours labor.
Estimated cost: $300-600
Hard pass unless heavily discounted and you have a substantial repair fund—these are ticking time bombs with multiple expensive failure points, particularly the engines and transmission cooling systems that routinely require $8,000+ repairs.
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.