The 2021 LC 500 is Lexus's flagship GT coupe built on a bespoke platform with the proven 2UR-GSE 5.0L V8 and 10-speed automatic. While exceptionally well-built and reliable compared to European competitors, it's not immune to specific issues inherited from the LS 500 and RC F platforms that share this powertrain.
Transmission Oil Cooler Line Leaks
Occasional · medium severityTypical onset: 40,000-70,000 mi
Symptoms: Transmission fluid spots under vehicle, typically passenger side, Low transmission fluid warning on dash, Slight burnt smell after highway driving, Pink-to-red fluid visible near front subframe
Fix: Replace transmission oil cooler lines and fittings where they connect to the radiator. The OEM crimped fittings can weep or crack under heat cycling. Requires front undertray removal and radiator support access. 2.5-3.5 hours labor depending on access.
Estimated cost: $800-1,400
Carbon Buildup on Intake Valves (Direct Injection)
Common · low severityTypical onset: 60,000-90,000 mi
Symptoms: Rough idle when cold, smooths out after warmup, Hesitation or stumble during light acceleration, Slightly reduced fuel economy, Check engine light with multiple misfire codes (P0300-P0308)
Fix: Walnut shell blasting of intake valves. This engine uses direct injection only (no port injection to clean valves). Requires intake manifold removal to access all eight cylinders. 6-8 hours labor for proper cleaning. Prevent with Italian tune-ups and quality fuel.
Estimated cost: $1,200-2,000
Transmission Mount Deterioration
Occasional · low severityTypical onset: 50,000-80,000 mi
Symptoms: Clunk when shifting from Park to Drive or Reverse, Vibration through center console at idle in Drive, Harsh engagement during low-speed shifts, Visible tearing or fluid seepage from mount rubber
Fix: Replace rear transmission mount. The AA80E 10-speed transmission weighs significantly more than previous 8-speeds, accelerating mount wear. Requires transmission support and subframe partial drop. 2-2.5 hours labor.
Estimated cost: $600-950
Fuel Injector Deposits and Flow Issues
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Intermittent rough running, especially under load, Reduced power output, sluggish throttle response, Check engine light with fuel trim or injector codes, Hard starting when hot (heat-soaked injectors)
Fix: Direct injectors can coke up or develop spray pattern issues. Professional ultrasonic cleaning often works initially, but some injectors fail internally. Replacement requires fuel rail removal and proper depressurization. 4-5 hours labor for diagnosis, cleaning, or replacement of all eight injectors.
Estimated cost: $1,500-3,200
Infotainment System Freezing and Rebooting
Occasional · low severitySymptoms: Screen goes black and reboots while driving, Touchpad becomes unresponsive intermittently, Navigation system crashes when switching inputs, Backup camera delayed or fails to display
Fix: Software glitch in the Lexus Enform system. Dealer TSB software update typically resolves. If hardware fault, head unit replacement required. 1-1.5 hours for software update, 3-4 hours for head unit replacement.
Estimated cost: $150-2,500
Front Suspension Knocking (Lower Control Arm Bushings)
Rare · medium severityTypical onset: 60,000-100,000 mi
Symptoms: Clunking over bumps from front end, especially at low speeds, Steering feels less precise or wanders slightly, Visible cracking in lower control arm bushings during inspection, Uneven tire wear on inner edges
Fix: Replace front lower control arms with bushings (bushings typically not sold separately). Requires alignment after replacement. 3-4 hours labor per side including alignment.
Estimated cost: $1,800-2,800
Yes—this is one of the most reliable high-performance GTs available, with problems that are minor compared to German rivals and a bulletproof V8, but budget for carbon cleaning and don't skip fluid services.
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.