The 2004 Toyota Supra doesn't exist as a production model — Toyota ended Supra production in 2002 (Japan market). If you mean a JDM 1993-2002 A80 Supra imported and titled as 2004, or you're referring to a 1993-1998 USDM model, the 2JZ-GTE turbo inline-six is legendary but not bulletproof when modified or neglected.
Blown Head Gasket (2JZ-GTE Factory Torque Spec Issue)
Common · high severityTypical onset: 60,000-100,000 mi or after aggressive tuning
Symptoms: White smoke from exhaust on cold start, Coolant loss with no visible leaks, Overheating under boost, Milky oil or bubbles in coolant reservoir
Fix: Factory head gasket and torque specs are marginal, especially on boosted cars. Requires head removal, resurfacing, ARP head studs, and metal head gasket. Labor: 12-16 hours if no machine work needed beyond decking.
Estimated cost: $2,500-4,500
Spun Rod or Main Bearings (Oil Starvation / Hard Launches)
Occasional · high severityTypical onset: 80,000-150,000 mi, or anytime after hard driving
Symptoms: Knocking or ticking noise from bottom end, especially when warm, Low oil pressure at idle, Metal shavings in oil filter or pan, Catastrophic failure: sudden loss of power, seizing
Fix: 2JZ oil pump is fine, but oil pickup can crack or hard launches starve cylinders 5-6. Requires crank removal, bearing replacement, crank polishing or replacement if scored. If pickup is cracked, full teardown. Labor: 20-30 hours for full bottom end rebuild.
Estimated cost: $4,000-8,000
Automatic Transmission Failure (A340E Overheating)
Common · high severityTypical onset: 100,000-150,000 mi, sooner if tuned or towing
Symptoms: Slipping between gears, especially 2nd to 3rd, Delayed or harsh engagement from Park, Burnt transmission fluid smell, Check engine light with shift solenoid codes
Fix: Factory trans cooler is undersized; fluid breaks down. Rebuild or replacement required once clutches burn. Upgrade cooler during repair. Labor: 10-14 hours for R&R and rebuild.
Estimated cost: $2,000-3,500
Turbo Failure (CT12B Stock Twins Aging Out)
Occasional · medium severityTypical onset: 120,000-180,000 mi
Symptoms: Blue smoke on acceleration, Loss of boost pressure, Whistling or grinding noise from engine bay, Oil consumption increases noticeably
Fix: Factory sequential turbos wear seals and bearings. Most owners upgrade to single turbo setup instead of rebuilding twins. Stock replacement: 14-18 hours labor. Single conversion: 20-25 hours.
Estimated cost: $2,500-5,000
Fuel Pump Failure (In-Tank Pump Weak or Dead)
Occasional · medium severityTypical onset: 100,000+ mi or after sitting
Symptoms: Hard starting or extended crank time, Stuttering or hesitation under acceleration, Fuel pump whine audible from rear seat area, Stalling after warm-up
Fix: Factory pump struggles with age and ethanol fuel. Drop tank, replace pump assembly. Many upgrade to Walbro 255 while in there. Labor: 3-4 hours.
Estimated cost: $400-800
Transmission Mount Collapse (Excessive Drivetrain Movement)
Common · low severityTypical onset: 80,000-120,000 mi
Symptoms: Clunking when shifting or launching, Vibration through shifter at idle, Excessive gear whine or grinding feel, Visible sagging when inspecting from underneath
Fix: Rubber mounts deteriorate and allow excessive movement. Replace transmission mount and inspect diff/subframe bushings. Labor: 2-3 hours.
Estimated cost: $300-600
Ignition System Misfires (Coil Packs and Wiring Harness)
Occasional · medium severityTypical onset: Not mileage-driven — age and heat cycles
Symptoms: Random misfires, especially under boost, Check engine light with P030X codes, Rough idle when cold, Crackling or arcing visible at night near coils
Fix: Factory coil packs crack, igniter fails, or harness insulation deteriorates in engine bay heat. Replace coils, plugs, and inspect harness for shorts. Labor: 3-5 hours if harness repair needed.
Estimated cost: $600-1,200
Buy only if you can verify maintenance history and accept that any 20+ year old turbo car will need $3k-5k in deferred maintenance — but the 2JZ's legendary potential makes it worth it for the right enthusiast.
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.