The 2014 RLX is Acura's flagship sedan built on a unique platform with either a 3.5L V6 or Sport Hybrid SH-AWD system. While generally reliable, it suffers from catastrophic engine failures on certain VIN ranges and transmission cooling issues that can lead to expensive repairs.
Catastrophic Engine Failure - Piston Ring Land Fracture
Occasional · high severityTypical onset: 60,000-120,000 mi
Symptoms: Excessive oil consumption (1+ quart per 1,000 miles), White/blue smoke from exhaust on cold start, Loss of power under load, Metallic knocking noise, Check engine light with misfire codes P0300-P0306
Fix: Engine requires complete teardown; piston ring lands crack due to design flaw causing oil consumption and eventual bearing failure. Most cost-effective solution is short block replacement or used engine swap. 25-35 hours labor depending on hybrid vs non-hybrid.
Estimated cost: $8,000-14,000
Transmission Oil Cooler Failure and Contamination
Common · high severityTypical onset: 70,000-110,000 mi
Symptoms: Transmission slipping or harsh shifts, Milky/strawberry-colored transmission fluid, Coolant loss with no visible leaks, Transmission overheating warnings, Sweet smell from exhaust
Fix: Internal ATF cooler in radiator fails, allowing coolant and ATF to mix. Requires radiator replacement, complete transmission fluid flush (multiple cycles), and often transmission rebuild if contamination reached clutch packs. 8-12 hours for cooler/flush, add 20+ hours if transmission needs rebuild.
Estimated cost: $1,200-2,500 (cooler/flush only), $4,500-7,000 (with transmission rebuild)
Sport Hybrid SH-AWD Battery Pack Degradation
Occasional · medium severityTypical onset: 100,000-150,000 mi
Symptoms: Reduced electric-only range, Battery warning lights, Increased engine runtime even at low speeds, IMA system errors, Vehicle defaults to gasoline-only mode
Fix: Lithium-ion battery pack cells degrade over time. Honda/Acura has had limited success with individual module replacement; most cases require complete battery pack replacement. 6-8 hours labor. Battery availability is becoming an issue as these age out.
Estimated cost: $3,500-6,000
Adaptive Cruise Control and Collision Mitigation System Failures
Common · medium severitySymptoms: CMBS error messages on startup, Adaptive cruise suddenly disengaging, False forward collision warnings, Camera calibration errors after windshield replacement
Fix: Forward-facing camera behind windshield is sensitive to moisture intrusion and calibration drift. Subject to recall but issues persist. Requires specialized diagnostic scanner and camera replacement or recalibration. 2-3 hours including calibration drive procedure.
Estimated cost: $800-1,500
Active Engine Mount Failures
Common · low severityTypical onset: 80,000-120,000 mi
Symptoms: Excessive vibration at idle when in Drive, Clunking when shifting from Park to Drive, Vibration at 1,500-2,000 RPM, Check engine light with mount control codes
Fix: Electronic-controlled engine mounts (especially front and transmission mounts) fail internally. Requires genuine Acura parts as aftermarket doesn't replicate the active dampening. 3-4 hours for front and transmission mounts together.
Estimated cost: $1,200-1,800
Jewel-Eye LED Headlight Module Failures
Occasional · low severitySymptoms: Individual LED elements not illuminating, Moisture inside headlight housing, Flickering on one side, Headlight warning on dash
Fix: The signature multi-LED 'Jewel Eye' headlights have individual LED failures and seal issues causing moisture intrusion. Complete headlight assembly replacement required; individual LED repair not available. Subject to recall but doesn't cover all failure modes. 1.5-2 hours per side.
Estimated cost: $1,500-2,200 per headlight assembly
Pass unless you find a meticulously-maintained low-mileage example with documented oil consumption testing and recent transmission service - the engine failure risk and transmission cooler issue make this a gamble even at attractive prices.
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.