The 2015 Highlander is generally solid, but the 2GR-FE 3.5L V6 can suffer catastrophic oil consumption leading to engine failure, while transmission oil cooler leaks are common across all powertrains. The hybrid variant adds complexity but avoids some V6 engine issues.
Excessive Oil Consumption / Engine Failure (3.5L V6)
Occasional · high severityTypical onset: 80,000-150,000 mi
Symptoms: Low oil light between changes, burning 1+ quart per 1,000 mi, Blue smoke on cold start or hard acceleration, Sudden engine knock or catastrophic failure if oil level drops critically, Carbon buildup on pistons and rings exacerbating the problem
Fix: Toyota's pistons and rings were susceptible to coking. Proper fix requires engine teardown, new pistons, rings, honing, and decarbonizing — 18-24 hours labor. Some engines are too far gone and need short block or full rebuild. Preventive: use quality synthetic, change every 5,000 mi, check oil weekly.
Estimated cost: $4,500-8,500
Transmission Oil Cooler Leak
Common · medium severityTypical onset: 60,000-120,000 mi
Symptoms: Pink or red fluid pooling under vehicle, driver's side, Transmission running hot or slipping under load, Low ATF level on dipstick (if equipped) or warning light
Fix: The internal oil cooler lines corrode where they connect to the radiator. Replace cooler lines and top off fluid — 2-3 hours labor. If caught early, no transmission damage. If run low, you're looking at a rebuild.
Estimated cost: $400-700
Transmission Mount Failure
Common · low severityTypical onset: 70,000-110,000 mi
Symptoms: Clunk or jolt when shifting from Park to Drive or Reverse, Excessive vibration at idle, especially with AC on, Visible sagging or torn rubber on the front mount
Fix: The front transmission mount is hydraulic and prone to fluid leakage and collapse. Replace mount — 1.5-2 hours labor. Aftermarket mounts are cheaper but OEM lasts longer.
Estimated cost: $250-450
Electric Power Steering (EPS) Failure
Rare · high severitySymptoms: Complete loss of power steering assist while driving, EPS warning light on dash, Heavy steering effort, especially at low speeds or parking
Fix: TSB and recall addressed some EPS ECU issues, but failure still happens. Diagnosis requires scanning for EPS codes; fix is usually EPS control module or motor assembly replacement — 3-4 hours labor. Safety critical — do not ignore warning light.
Estimated cost: $1,200-2,000
Water Pump Weeping (3.5L V6)
Occasional · medium severityTypical onset: 90,000-130,000 mi
Symptoms: Coolant smell in cabin or under hood, Pink residue or dried coolant on water pump housing, Slight coolant loss over time, no visible external leaks
Fix: The 2GR-FE water pump is buried behind the timing cover. Replace pump, timing cover gasket, and coolant — 4-5 hours labor. Do the thermostat at the same time since you're in there.
Estimated cost: $800-1,300
EVAP Purge Valve / Fuel System Codes
Occasional · low severityTypical onset: 60,000-100,000 mi
Symptoms: Check engine light with P0441, P0446, or P0455 codes, Rough idle or stalling after refueling, Fuel smell near charcoal canister area
Fix: EVAP purge valve sticks or the charcoal canister saturates. Replace purge valve and inspect canister and lines for cracks — 1-1.5 hours labor. Won't strand you but fails emissions testing.
Estimated cost: $200-400
Buy the 2.7L I4 or Hybrid if you can live with less power — avoid the 3.5L V6 unless you can verify it's not burning oil and has religious maintenance 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.