The 2021 G80 is largely solid but shows concerning early engine failures on the 2.5T variant, plus scattered fuel system issues that triggered multiple recalls. The 3.8L V6 has proven far more reliable in the field.
2.5L Turbo Catastrophic Engine Failure (Theta II derivative)
Occasional · high severityTypical onset: 30,000-70,000 mi
Symptoms: Sudden knocking or rod-bearing noise, Metal shavings in oil, Check engine light with misfire codes, Complete loss of power
Fix: Short block replacement or full engine rebuild required. Seen connecting rod bearing failures and piston ring land fractures. Often covered under warranty if under 60k mi, but out-of-pocket is brutal. 18-24 labor hours for short block swap.
Estimated cost: $8,000-14,000
Fuel Line Fitting Leaks (NHTSA Recall Coverage)
Common · high severitySymptoms: Fuel odor in cabin or around engine bay, Visible wetness on fuel lines near engine, Fuel smell after hot soak, Potential fire risk
Fix: Recalls address hose clamps and quick-connect fittings on high-pressure fuel lines. Dealer recall service replaces affected components at no cost. Do NOT delay—fire hazard is real. 1.5-2 hours typical repair time.
Estimated cost: $0 (recall)
Transmission Oil Cooler Line Leaks
Occasional · medium severityTypical onset: 40,000-80,000 mi
Symptoms: Transmission fluid spots under vehicle, Burnt smell from engine bay, Transmission temp warning light, Fluid level dropping on dipstick check
Fix: Cooler line connections at radiator and transmission corrode or crack. Replace lines and top off fluid. Sometimes the cooler itself weeps. 2-3 hours labor depending on access.
Estimated cost: $400-800
Transmission Mount Deterioration (8-speed models)
Occasional · low severityTypical onset: 50,000-90,000 mi
Symptoms: Clunk on 1-2 upshift or downshift into 1st, Vibration at idle in Drive, Excessive driveline movement felt through chassis
Fix: Hydraulic transmission mount fails prematurely on heavier G80. Replace mount—straightforward job. 1.5-2 hours with proper lift access.
Estimated cost: $350-600
Fuel Pump Failure (2.5T primarily)
Rare · high severityTypical onset: 20,000-50,000 mi
Symptoms: No-start condition, Stumbling or surging at highway speed, Fuel pump whine audible from rear seat, Loss of power under load
Fix: In-tank fuel pump recall for some VINs (check NHTSA database). Non-recall failures also documented—replace pump module. 2-3 hours including tank drop or access panel removal.
Estimated cost: $800-1,400
Front Seat Belt Pre-tensioner Defect (Recall)
Rare · high severitySymptoms: Seat belt warning light stays on, Belt does not retract properly, Pre-tensioner may not deploy in crash
Fix: Recall replaces faulty seat belt retractor assemblies. No cost to owner. Get it done—safety system integrity is non-negotiable. 1 hour per seat.
Estimated cost: $0 (recall)
Buy the 3.8L V6 with a clean recall history and you'll likely be fine; avoid the 2.5T unless you enjoy playing engine-failure roulette or have a bulletproof warranty.
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.