The 2014 Highlander is generally a solid mid-size SUV, but the 2.7L four-cylinder has critical engine durability issues, and the V6 models suffer from a specific transmission cooler problem that can destroy the transmission if ignored.
2.7L I4 Excessive Oil Consumption and Piston Ring Failure
Common · high severityTypical onset: 60,000-120,000 mi
Symptoms: Blue smoke from exhaust on startup or acceleration, Burning through 1+ quart oil every 1,000 miles, Check engine light P0301-P0304 misfire codes, Carbon buildup on spark plugs
Fix: Engine rebuild or replacement required — piston rings fail and score cylinder walls. 20-30 labor hours for full rebuild including new pistons, rings, honing, head gasket set. Some warranty extensions existed but coverage ended. Many shops recommend reman long-block swap instead of rebuild due to cylinder wall damage.
Estimated cost: $4,500-7,500
Transmission Oil Cooler Line Failure (V6 models)
Common · high severityTypical onset: 80,000-150,000 mi
Symptoms: Pink milkshake in coolant reservoir (trans fluid mixing with coolant), Transmission slipping or delayed engagement, Overheating transmission, Coolant loss with no external leaks
Fix: The transmission cooler inside the radiator fails and allows ATF and coolant to mix — destroys transmission if driven. Requires radiator replacement, complete transmission fluid flush (often multiple exchanges), and if caught late, transmission rebuild. 3-4 hours if caught early, 15-25 hours if transmission damaged.
Estimated cost: $800-1,200 (early catch) / $3,500-5,500 (with transmission damage)
Rear Differential Pinion Seal Leak
Occasional · medium severityTypical onset: 70,000-130,000 mi
Symptoms: Gear oil drips or puddles under rear of vehicle, Visible oil on differential housing, Low differential fluid level on inspection
Fix: Pinion seal fails on AWD models. Requires removing driveshaft, pinion nut, flange, and replacing seal with proper crush sleeve procedure. If run low on fluid, can damage ring and pinion. 2.5-3.5 hours labor.
Estimated cost: $350-600
Front Lower Control Arm Bushing Deterioration
Common · medium severityTypical onset: 90,000-140,000 mi
Symptoms: Clunking over bumps from front suspension, Wandering or loose steering feel, Uneven tire wear on inside edge, Failed alignment — won't hold settings
Fix: OEM bushings are soft and fail early, especially in hot climates. Must replace entire control arm assemblies as bushings aren't serviceable separately on this generation. Both sides typically done together. 2.5-3 hours labor per side, alignment required.
Estimated cost: $700-1,100 (both sides with alignment)
Transmission Mount Failure
Occasional · low severityTypical onset: 80,000-120,000 mi
Symptoms: Clunk when shifting from Park to Drive or Reverse, Vibration at idle in gear, Excessive engine movement visible when accelerating
Fix: Hydraulic transmission mount deteriorates and loses damping. Simple R&R job but requires supporting engine/transmission properly. 1.5-2 hours labor.
Estimated cost: $250-400
Evaporative Emissions System Charcoal Canister Saturation
Occasional · low severitySymptoms: Check engine light P0441 or P0446 EVAP codes, Difficulty fueling — pump clicks off repeatedly, Fuel smell after filling tank
Fix: Charcoal canister saturates with liquid fuel from repeated topping-off during fueling. Requires canister replacement and sometimes purge valve. 1.5-2 hours labor. Preventable by not topping off tank.
Estimated cost: $350-550
Avoid the 2.7L I4 entirely; the 3.5L V6 is a good buy if the transmission cooler has been addressed or replaced preventively, but budget for that repair if buying high-mileage.
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.