The 2015 ATS is a competent rear-drive sport sedan undermined by catastrophic 2.0T engine failures and transmission cooling issues. The 2.5L is bulletproof but boring; the 3.6L is more reliable than the turbo but drinks premium fuel.
2.0L Turbo Catastrophic Engine Failure (Piston Ring/Bearing Collapse)
Common · high severityTypical onset: 60,000-100,000 mi
Symptoms: Excessive oil consumption (quart per 1,000 mi or worse), Metallic knocking from crankcase, Check engine light with misfire codes, Loss of compression, Sudden seizure or rod knock
Fix: Total engine failure requiring short block or complete engine replacement. Carbon buildup starves rings, leading to blow-by and bearing damage. Warranty extensions existed but many are expired now. 16-24 labor hours for removal, replacement, break-in.
Estimated cost: $7,000-12,000
Transmission Oil Cooler Line Leaks and Cooler Failure
Common · high severityTypical onset: 50,000-90,000 mi
Symptoms: Transmission fluid dripping from center of vehicle, Burnt transmission fluid smell, Slipping or harsh shifts, Transmission overheating warnings
Fix: The 8-speed auto's cooler lines corrode where they connect to the radiator-mounted cooler, or the cooler itself fails internally. Requires cooler replacement, lines, and full fluid flush. If driven low on fluid, internal transmission damage follows. 4-6 labor hours.
Estimated cost: $800-1,800
CUE Infotainment System Freezing and Touchscreen Failure
Common · low severitySymptoms: Touchscreen unresponsive or only partially responsive, System reboots randomly, Climate controls inaccessible, Bluetooth and nav failures
Fix: Early CUE systems have notoriously unreliable touchscreens and processor modules. Fixes range from software reflashes (1 hour) to complete CUE module replacement (3-4 hours). GM issued TSBs but no permanent solution for early units.
Estimated cost: $150-2,500
Transmission Mount Failure (Rear)
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Clunking when shifting from Park to Drive, Vibration at idle in gear, Excessive drivetrain movement over bumps, Visible torn rubber on mount inspection
Fix: The rear transmission mount tears due to the torque from the turbo or V6. Requires lift access and subframe support. OEM mount recommended over aftermarket. 2-3 labor hours.
Estimated cost: $350-600
Sunroof Drain Tube Clogs and Water Intrusion
Occasional · medium severitySymptoms: Water pooling in footwells (front or rear), Wet headliner around sunroof, Musty smell, Electrical gremlins (modules getting wet)
Fix: Drain tubes clog with debris, causing water to back up into cabin. Requires tube cleaning/snake, sometimes tube replacement if cracked. If water damaged modules (common: BCM, seat modules), repair costs skyrocket. Preventive cleaning: 1 hour; full repair with module replacement: 6-10 hours.
Estimated cost: $150-2,000
Timing Chain Stretch (2.0T)
Occasional · high severityTypical onset: 80,000-130,000 mi
Symptoms: Rattle on cold start for 2-3 seconds, Check engine light with cam/crank correlation codes, Rough idle, Loss of power
Fix: The 2.0T's timing chain stretches if oil changes are neglected or wrong oil used. Requires front engine disassembly, timing set replacement, and often VVT solenoids. If chain jumps timing, valve damage occurs. 10-14 labor hours.
Estimated cost: $2,200-4,000
Electronic Power Steering Failures
Rare · high severityTypical onset: 60,000-100,000 mi
Symptoms: Sudden complete loss of power steering assist, Steering becomes extremely heavy, Warning message: 'Power Steering Assist Fault'
Fix: Electric power steering motor or control module fails, leaving manual steering only. Dangerous in traffic. Module replacement requires programming; motor requires column removal. 3-5 labor hours depending on component.
Estimated cost: $1,200-2,200
Skip the 2.0T entirely due to engine failure epidemic; a 2.5L or 3.6L V6 example under 60k miles with full records might be worth $12-15k, but factor $2-3k repair buffer for transmission and CUE 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.