The 2012 DB9's naturally-aspirated 6.0L V12 is legendary but fragile—bore scoring and bottom-end failures dominate the high-mileage conversation. The Touchtronic II transmission and associated cooler/mount issues add to ownership anxiety, while electrical gremlins and hydraulic latch problems keep specialists busy.
Catastrophic Bore Scoring and Piston Failure
Common · high severityTypical onset: 50,000-90,000 mi
Symptoms: Excessive oil consumption (1+ quart per 1,000 miles), Blue smoke on cold start or under load, Metallic ticking or knocking from cylinder bank, Loss of compression on cylinder leak-down test
Fix: Requires engine-out for cylinder sleeve repair or complete short-block replacement. Reputable shops spend 60-80 hours on full rebuild with bore correction, piston/ring replacement, and reassembly. Some engines receive factory sleeves, others get aftermarket Nikasil re-coating. Budget high—this is the DB9's Achilles heel.
Estimated cost: $25,000-45,000
Main and Rod Bearing Wear Leading to Bottom-End Failure
Occasional · high severityTypical onset: 70,000-120,000 mi
Symptoms: Deep knocking on cold start that fades as oil pressure builds, Low oil pressure warning on dash, Metallic debris in oil filter media, Audible rumble under acceleration
Fix: Engine must come out for crank removal, bearing replacement, and journal inspection/polishing. If the crank is scored, replacement or grinding is required. Conservative approach: inspect pistons/bores while apart. 50-70 labor hours for bearing replacement alone; expect more if crank needs machining.
Estimated cost: $18,000-32,000
Transmission Oil Cooler Failure and Transmission Mount Collapse
Common · medium severityTypical onset: 60,000-100,000 mi
Symptoms: ATF leaking onto subframe or puddling under car, Harsh shifts or clunking during 1-2 or 2-3 upshift, Visible sagging of transmission tunnel or drivetrain vibration, Pink fluid visible near front cooler lines
Fix: Oil cooler replacement requires front undertray removal and cooling system partial drain—4-6 hours. Transmission mounts are hidden and labor-intensive; expect 6-8 hours to drop the exhaust, crossmember, and trans enough to swap mounts. Both jobs often done together since access overlaps.
Estimated cost: $2,800-5,500
Door and Trunk Latch Hydraulic Actuator Failure
Common · low severitySymptoms: Door or trunk won't open from outside but interior release works, Slow or delayed latch operation—takes 2-3 seconds to pop, No response from key fob but alarm arms/disarms normally, Audible hissing or faint click with no mechanical movement
Fix: Each door/trunk has a hydraulic actuator that fails due to internal seal degradation. Replacement requires door panel or trunk liner removal; 2-3 hours per latch. OEM parts are expensive but aftermarket rebuilds exist. Front doors are easier than rear or trunk.
Estimated cost: $800-1,800
Accelerator Pedal Position Sensor Fault (Recall Item)
Occasional · medium severitySymptoms: Throttle sticks partially open or closed—dangerous in traffic, Check engine light with P2138 or P2135 throttle correlation codes, Limp mode activation—engine limited to idle or 2,000 RPM, Intermittent loss of throttle response requiring key cycle
Fix: Covered under NHTSA recall; dealer replaces pedal assembly and updates ECU calibration. If outside recall window, pedal replacement is 1-2 hours. Verify recall completion on any used purchase—this is a safety issue.
Estimated cost: $400-900
Fuel Filter Clogging and High-Pressure Pump Starvation
Occasional · medium severityTypical onset: 40,000-80,000 mi
Symptoms: Rough idle or hesitation under hard acceleration, Misfires at high RPM (5,000+ RPM) under load, Long crank time on hot restarts, Fuel trim values out of range on scanner
Fix: In-tank fuel filter is not a scheduled maintenance item but clogs from ethanol varnish and debris. Tank must drop for filter access—6-8 hours labor. Replace filter, inspect pump strainer, and clean pickup while apart. Some shops recommend fuel system flush during reassembly.
Estimated cost: $1,800-3,200
Buy only with comprehensive pre-purchase inspection including bore-scope and oil analysis—budget $10k cushion for inevitable engine or transmission work, or walk away if you can't afford the risk.
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.