The 2017 Highlander is generally reliable, but the 3.5L V6 has a critical oil consumption defect that can destroy engines, and the 8-speed transmission in non-hybrid models has premature failure issues. Hybrids are significantly more durable.
3.5L V6 Excessive Oil Consumption / Piston Ring Failure
Common · high severityTypical onset: 60,000-120,000 mi
Symptoms: Low oil light between changes, burning 1+ quart per 1,000 miles, Blue exhaust smoke on cold starts or acceleration, Carbon buildup on intake valves causing rough idle and hesitation, Catastrophic engine failure if oil level drops unnoticed
Fix: Piston ring replacement requires full engine teardown (25-35 hours). Many shops recommend short block or remanufactured engine instead due to labor overlap. Toyota extended warranty to 10yr/150k on some VINs but many 2017s excluded. Oil consumption test required for warranty coverage.
Estimated cost: $4,500-8,500
8-Speed Automatic Transmission Failure (Non-Hybrid)
Occasional · high severityTypical onset: 80,000-140,000 mi
Symptoms: Harsh 2-3 or 3-4 shifts, especially when cold, Shuddering or slipping during acceleration from stop, Transmission fault codes P0793 (intermediate shaft speed sensor), Complete loss of forward gears, limp mode
Fix: Internal clutch pack wear and valve body issues. Fluid changes every 30k help but don't prevent it. Rebuild requires 18-24 hours; many opt for remanufactured unit. Oil cooler lines also prone to leaks and should be inspected during service.
Estimated cost: $3,800-6,200
Transmission Oil Cooler Line Leaks
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Reddish fluid dripping under vehicle near front wheels, Low transmission fluid warning or shifting issues, Lines corrode where they connect to radiator assembly
Fix: Steel lines rust through at fittings. Replace both feed and return lines as a pair (3-4 hours). Sometimes requires radiator removal for access. Check for internal radiator contamination if leak went unnoticed long.
Estimated cost: $600-950
Fuel Pump Failure (Recall 20V-490 Related)
Occasional · high severitySymptoms: Engine stalls without warning, no restart until cool, Rough running, surging at highway speed, Check engine light with fuel pressure codes P0087, P0089, Non-start condition, cranks but won't fire
Fix: Low-pressure fuel pump inside tank fails due to manufacturing defect. Recall covers some VINs but not all 2017s qualified. Replacement requires tank drop (4-5 hours). Use OEM pump only—aftermarket units fail within 20k miles.
Estimated cost: $1,200-1,800
Front Engine Mount / Transmission Mount Failure
Common · low severityTypical onset: 90,000-130,000 mi
Symptoms: Clunk or thud when shifting from Park to Drive, Vibration at idle, especially with A/C on, Visible engine movement when revving in Park
Fix: Hydraulic mounts leak fluid and collapse. Front and transmission mounts most common. Replace as pairs for best results (3-4 hours combined). Failure won't strand you but makes vehicle unpleasant to drive.
Estimated cost: $550-850
Direct Injection Carbon Buildup (3.5L V6)
Common · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Rough idle, misfires on cold start, Hesitation or stumble during light acceleration, Check engine light with misfire codes P0300-P0306, Reduced fuel economy and throttle response
Fix: Direct injection engines have no fuel washing intake valves. Requires walnut blasting (6-8 hours) to remove deposits. Preventive: use top-tier fuel, Italian tune-up monthly. Some owners add catch cans but results vary.
Estimated cost: $600-1,100
Buy the hybrid if possible—bulletproof drivetrain. Non-hybrid V6 is a gamble on oil consumption; budget $5k-8k for potential engine work or walk away.
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.