The 2003 Eclipse is a fun, affordable sporty coupe undermined by automatic transmission fragility and chronic crankshaft walk on the V6. The 2.4L four-cylinder is significantly more reliable, but both engines suffer from mediocre oil control as miles pile on.
Automatic Transmission Failure (4-Speed F4A42)
Common · high severityTypical onset: 80,000-130,000 mi
Symptoms: Harsh or delayed 2-3 upshift, especially when warm, Slipping under acceleration or complete loss of forward gears, Burnt transmission fluid smell, dark brown or black fluid color, Check engine light with P0700, P0734, or solenoid codes
Fix: Rebuild or replacement required; these automatics rarely survive a flush or solenoid swap once symptoms appear. Budget 8-12 hours labor for R&R plus rebuild, or 6-8 hours for a used unit swap. Cooler lines often corroded and should be replaced during job.
Estimated cost: $2,200-3,800
Crankshaft Endplay / Thrust Bearing Wear (3.0L V6)
Occasional · high severityTypical onset: 90,000-150,000 mi
Symptoms: Metallic knocking or rumbling at idle, worsens with clutch engagement on manuals, Vibration through chassis that changes with RPM, Oil pressure fluctuations or low pressure warning, Catastrophic failure results in no-start, severe engine noise, or locked motor
Fix: Requires full engine teardown to replace thrust bearings and machine or replace crankshaft if journals are damaged. This is the 6G72's Achilles heel—often discovered too late. 18-25 hours labor for in-frame rebuild; many shops recommend short block swap instead at 12-16 hours.
Estimated cost: $3,500-5,500
Head Gasket Failure (2.4L 4G64)
Occasional · medium severityTypical onset: 100,000-160,000 mi
Symptoms: Overheating with no external coolant leaks, White smoke from exhaust, sweet smell, Milky oil or coolant loss without visible puddles, Bubbling in overflow tank at idle
Fix: Head gasket replacement with machine shop resurface. Must check head for warpage; if over 0.008 inch out of spec, head replacement needed. 10-14 hours labor including timing belt service which should be done simultaneously.
Estimated cost: $1,800-2,800
Transmission Oil Cooler Line Corrosion
Common · medium severityTypical onset: 70,000-120,000 mi
Symptoms: Red fluid puddles under engine bay, near radiator, Transmission running hotter than normal, Low transmission fluid without visible leak from pan, Occasional slipping if fluid level drops significantly
Fix: Replace both cooler lines and fittings; corrosion typically affects steel sections near radiator and frame mounts. 2-3 hours labor. Flush system and verify radiator-mounted cooler isn't cross-contaminating coolant and ATF.
Estimated cost: $350-650
Rear Main Seal and Oil Pan Gasket Leaks
Common · low severityTypical onset: 90,000-140,000 mi
Symptoms: Oil spots on driveway, centered under bellhousing area, Oily residue on bottom of transmission bellhousing, Burning oil smell after highway driving, Gradual oil consumption, 1 quart per 1,500-2,500 miles
Fix: Rear main seal requires transmission removal: 6-8 hours labor on manual, 8-10 on automatic. Oil pan gasket is simpler at 3-4 hours but access is tight. Often both are done together since labor overlaps significantly.
Estimated cost: $800-1,600
Fuel Pump Failure (Recall 04V-331 Related)
Occasional · high severityTypical onset: 80,000-140,000 mi
Symptoms: No-start or extended cranking, especially when tank below 1/4 full, Intermittent stalling at idle or during acceleration, Whining or buzzing noise from rear seat area, Check engine light with P0230, P0231 fuel pump circuit codes
Fix: Drop fuel tank for pump module replacement; straps and filler neck often corroded and need replacement. 3-5 hours labor. Verify recall 04V-331 was completed; if not, dealer may cover even out of warranty window.
Estimated cost: $600-1,100
Front Engine and Transmission Mounts
Common · low severityTypical onset: 60,000-100,000 mi
Symptoms: Clunking when shifting from park to drive or reverse, Excessive vibration at idle, especially with A/C on, Engine rocks noticeably during hard acceleration, Shifter vibration in manual transmission cars
Fix: Replace front and rear engine mounts plus transmission mount as a set; doing one at a time accelerates wear on others. 3-4 hours labor for all three. Hydraulic mounts fail internally and cannot be visually inspected reliably.
Estimated cost: $450-800
Buy the 2.4L manual if you want one—avoid the V6 and automatic at all costs unless you have service records proving preventive transmission and thrust bearing work.
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.