2022 GMC SIERRA 1500

Typical onset: 20,000-60,000 mi

Symptoms: Sudden loss of power, excessive white or blue smoke, Metallic knocking or rattling from engine bay, Oil consumption jumps dramatically before failure, Check engine light with misfire codes across multiple cylinders

Fix: Complete engine replacement or rebuild. Piston ring failures, spun bearings, and crankshaft damage are documented. If under warranty, GM covers it—out of warranty this is a $15,000-25,000 job. Rebuild takes 25-35 hours, replacement shortblock 18-24 hours. Many shops won't touch a Duramax rebuild; you're looking at dealer or specialty diesel shop.

Estimated cost: $15,000-25,000

Symptoms: Harsh or delayed shifts, especially 2-3 and 3-4, Transmission slipping in higher gears under moderate throttle, Service transmission warning on dash, Truck stuck in limp mode (3rd gear only)

Fix: Multiple TSBs and recalls address TCM software. Reflash takes 1.5-2 hours at dealer (often free under recall/warranty). If software doesn't fix it, you're looking at valve body replacement (8-10 hours) or transmission oil cooler contamination (3-4 hours). Cooler failures can send metal through the transmission, requiring full rebuild.

Estimated cost: $0-4,500

Typical onset: 30,000-70,000 mi

Symptoms: Red ATF pooling under truck near front crossmember, Transmission temperature warning light, Burnt smell from engine bay, Low transmission fluid level on dipstick

Fix: Steel cooler lines corrode at mounting points and connection fittings despite truck's age—salt and moisture accelerate this. Line replacement is 3-4 hours depending on access. If cooler itself fails internally, metal shavings contaminate the transmission requiring flush or rebuild. Always replace lines and cooler together.

Estimated cost: $800-1,400

Symptoms: Check engine light with P0544, P0546 codes, Louder engine cooling fan noise at idle, Slightly reduced fuel economy (1-2 MPG), Shutters visible stuck open or closed behind front grille

Fix: Electric motor or plastic linkage breaks—recall covers some units but not all. Diagnosis 0.5 hours, replacement 1.5-2 hours. Technically driveable but you lose aerodynamic efficiency and engine takes longer to warm up. Dealer part often on backorder 4-8 weeks.

Estimated cost: $400-700

Symptoms: Brake lights stay on continuously or don't work at all, Cruise control randomly disengages, Push-button start refuses to work, Shift interlock won't release from Park

Fix: Recall addresses some switch failures but harness chafing behind pedal assembly also causes intermittent faults. Switch replacement 0.8 hours, harness repair 2-3 hours if wiring damaged. This is a safety issue—you're invisible to cars behind you or constantly burning out bulbs.

Estimated cost: $150-600

Typical onset: 40,000-80,000 mi

Symptoms: Ticking or tapping noise from valve covers at cold start, Check engine light with P0300-series misfire codes, Metal shavings in oil during change, Rough idle that smooths out above 1500 RPM

Fix: GM's Dynamic Fuel Management (evolution of AFM) still eats lifters and cam lobes. If caught early, lifter replacement on affected bank is 12-15 hours. If cam is damaged, you're doing both heads and cam—25-30 hours plus machine work. Aftermarket AFM delete kits available but void powertrain warranty.

Estimated cost: $3,500-8,000