The 2012 Challenger spans from practical V6 commuters to fire-breathing SRT8s on the LX platform. The Pentastar V6 and 5.7 Hemi are solid, but transmission cooling issues and Hemi-specific valvetrain problems define the ownership experience at higher mileages.
Transmission Oil Cooler Failure & Contamination
Common · high severityTypical onset: 60,000-100,000 mi
Symptoms: Pink milkshake appearance in coolant overflow (ATF mixing with coolant), Transmission slipping or delayed engagement after cooler failure, Overheating transmission temp gauge readings, Strawberry milkshake residue in radiator
Fix: The internal trans cooler in the radiator fails and cross-contaminates coolant and ATF. Requires radiator replacement, complete transmission flush (often multiple flushes), new trans filter, and fresh fluids. If caught late, transmission rebuild or replacement needed. 4-6 hours labor for cooler/flush, add 12-20 hours if trans is damaged.
Estimated cost: $800-1,200 if caught early, $3,500-5,500 with transmission damage
5.7L Hemi Valvetrain Failure (Cam/Lifter/Rocker)
Occasional · high severityTypical onset: 80,000-150,000 mi
Symptoms: Ticking or tapping noise from engine that worsens with RPM, Check engine light with misfire codes (P0300-P0308), Loss of power, rough idle, Metal shavings in oil during changes
Fix: The Hemi's MDS (cylinder deactivation) lifters stick or fail, damaging cam lobes and rocker arms. Requires heads-off repair: replace all lifters, camshaft, rockers, and often pushrods. Some engines need full rebuilds if metal contamination is severe. 16-24 hours labor for proper cam/lifter job.
Estimated cost: $3,500-6,500 for cam/lifter replacement, $6,000-9,000 if short block damage occurs
Alternator Failure with Electrical Gremlins
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Battery warning light intermittent or constant, Dimming headlights, flickering dash lights, No-start condition or dead battery after short sits, Weird electrical behavior (windows, radio cutting out)
Fix: Factory alternators fail and cause voltage regulation issues that confuse PCM and BCM. The 160-amp units on V8s fail more often. Replace alternator and test battery (often needs replacement too from repeated deep discharge). 1.5-2.5 hours labor, add diagnostics time if chasing electrical ghosts afterward.
Estimated cost: $450-750 including battery if needed
Rear Transmission Mount Collapse
Common · low severityTypical onset: 50,000-90,000 mi
Symptoms: Clunk when shifting from park to drive or reverse, Vibration through chassis at idle in gear, Excessive driveline movement visible during hard acceleration, Metallic bang on deceleration
Fix: The rubber trans mount separates or tears, allowing excessive driveline movement. Worst on V8 cars with spirited driving. Simple replacement with aftermarket poly mounts recommended for longevity. 1-1.5 hours labor.
Estimated cost: $250-400
3.6L Pentastar Head Gasket Leaks (Left Cylinder Head)
Occasional · medium severityTypical onset: 90,000-140,000 mi
Symptoms: External coolant leak from left (driver) side of engine, Sweet coolant smell after driving, Slow coolant loss without visible puddles, White residue on left cylinder head near gasket mating surface
Fix: The left-side head gasket weeps externally on Pentastars. Not catastrophic but needs addressing before it worsens. Requires head removal, resurfacing check, new gasket, and timing chain inspection while in there. 8-10 hours labor.
Estimated cost: $1,800-2,800
EVAP System / Fuel Tank Pressure Sensor Faults
Occasional · low severityTypical onset: 60,000-100,000 mi
Symptoms: Check engine light with P0455, P0456, or P0457 codes (EVAP leak), Difficulty fueling (pump clicks off repeatedly), Gas cap light illuminated, Failed emissions testing
Fix: Fuel tank pressure sensor fails or EVAP purge valve sticks. Sometimes it's just a bad gas cap ($20), but often requires dropping the tank for sensor replacement or canister service. Diagnosis critical here. 2-4 hours labor if tank drop needed.
Estimated cost: $300-700 depending on component
V6 Pentastar models are decent buys with fluid maintenance discipline; 5.7 Hemis are ticking time bombs past 100k without immaculate service records—buy on condition, not price.
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.