The 2016 Highlander is generally solid, but the 2.7L I4 has catastrophic oil consumption issues leading to engine failure, while the 3.5L V6 remains one of Toyota's most reliable powertrains with minimal issues across typical ownership.
2.7L I4 Severe Oil Consumption and Engine Failure
Common · high severityTypical onset: 40,000-80,000 mi
Symptoms: Burning 1+ quart every 1,000 miles, Blue smoke from exhaust on startup, Check engine light with misfire codes, Complete engine seizure if oil runs dry
Fix: Piston ring design flaw causes oil to burn past rings into combustion chamber. Toyota issued TSB but no recall. Requires complete engine rebuild (piston rings, cylinder honing) at 18-25 hours, or short block replacement at 20-28 hours. Many owners only discover when engine is already damaged beyond simple ring replacement.
Estimated cost: $4,500-8,500
Transmission Oil Cooler Line Corrosion and Leaks
Occasional · medium severityTypical onset: 80,000-130,000 mi
Symptoms: Transmission fluid puddles under vehicle, Pink or red fluid near radiator area, Transmission slipping or delayed engagement if fluid level drops, Visible rust or wet spots on steel cooler lines
Fix: Steel transmission cooler lines rust through where they route along frame rails, especially in salt-belt states. Lines run from transmission to radiator-mounted cooler. Replacing both lines and connections takes 2.5-4 hours depending on access and corroded fasteners. Some techs replace with upgraded braided stainless aftermarket lines.
Estimated cost: $350-650
Front Engine Mount (Transmission Mount) Failure
Occasional · low severityTypical onset: 90,000-140,000 mi
Symptoms: Clunk or thud when shifting from Park to Drive, Excessive vibration at idle in Drive, Visible engine rocking when accelerating hard, Metal-on-metal contact sound during throttle transitions
Fix: Hydraulic front engine mount (often called transmission mount in Toyota parts system) degrades and loses fluid, allowing excessive drivetrain movement. V6 models particularly affected due to torque. Replacement requires supporting engine from above or below, takes 1.5-2.5 hours. OEM mount strongly recommended over aftermarket.
Estimated cost: $280-450
3.5L V6 Water Pump Bearing Failure
Occasional · medium severityTypical onset: 100,000-150,000 mi
Symptoms: Squealing or grinding noise from front of engine, Coolant weeping from pump weep hole, Rough bearing feel when rotating pump pulley by hand, Overheating if pump fails completely
Fix: The 2GR-FE water pump bearings can fail before the rest of the pump shows wear. Since this is a timing belt engine, smart shops replace water pump during any timing belt service (due every 90k). Pump alone is 2-3 hours, but done with timing belt at 5-6 hours total for complete service including tensioner and idlers.
Estimated cost: $450-750 (pump only), $900-1,400 (with timing belt)
Rear Hatch Strut Failure and Alignment Issues
Common · low severityTypical onset: 70,000-110,000 mi
Symptoms: Power liftgate slowly sags or won't stay open, Liftgate closes too fast or slams, Misaligned liftgate causing wind noise or water leaks, Liftgate motor straining or making grinding sounds
Fix: Gas struts wear out and lose pressure, causing liftgate to drop or close violently. If ignored, puts extra strain on liftgate motor and can bend hinge mounting points. Strut replacement is simple (0.5 hours), but if hinge points are bent from prolonged strain, realignment adds 1-2 hours. Replace both struts as a pair.
Estimated cost: $180-320 (struts only), $400-650 (if hinge/alignment work needed)
Hybrid Inverter Coolant Pump Failure (Hybrid Only)
Occasional · high severityTypical onset: 120,000-180,000 mi
Symptoms: Hybrid system warning light, Reduced power or 'turtle mode', Inverter overheating codes (P0A94, P0A9A), Coolant pump motor not running (testable with scan tool)
Fix: Electric coolant pump that cools the hybrid inverter fails, causing inverter to overheat and shut down hybrid system. Vehicle still drives on engine alone but with severely reduced power. Pump is 2-3 hours labor to replace, requires partial coolant drain and accessing pump under inverter assembly. Aftermarket pumps have shorter lifespan than OEM.
Estimated cost: $650-950
Buy the 3.5L V6 or hybrid without hesitation; avoid the 2.7L I4 entirely unless you have full service records proving no oil consumption issues.
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.