2008 CHEVROLET SILVERADO 2500HD

Typical onset: 100,000-180,000 mi

Symptoms: white smoke on cold start, rough idle, fuel in coolant, loss of power, metallic knocking from engine, melted pistons found on teardown

Fix: Failed injectors dump raw fuel into cylinders, washing down cylinder walls and cracking pistons. Requires complete engine rebuild: pistons, rings, machine work, injectors, head gaskets. 40-60 hours labor depending on cab-off vs cab-on approach. Many shops pull cab for access. If caught early (just injectors), 8-12 hours labor, but most owners ignore symptoms too long.

Estimated cost: $8,000-15,000

Typical onset: 80,000-150,000 mi

Symptoms: transmission fluid in coolant or coolant in transmission, milky fluid on dipstick, overheating, erratic shifting, transmission slipping

Fix: Internal cooler in radiator fails, cross-contaminating fluids and destroying transmission. Requires radiator replacement, complete transmission flush or rebuild, and cooler line replacement. If caught before internal damage: 4-6 hours. If transmission contaminated: add 18-25 hours for rebuild. External auxiliary cooler is mandatory after repair.

Estimated cost: $1,200-6,500

Typical onset: 120,000-200,000 mi

Symptoms: hard starting, low rail pressure codes (P0087, P0093), metal shavings in fuel filter, loss of power under load, black smoke

Fix: CP3 high-pressure pump sheds metal internally, contaminating entire fuel system. Requires pump replacement plus all eight injectors, both fuel rails, fuel filter housing, and complete system flush. 14-18 hours labor. Using low-quality or contaminated diesel accelerates failure.

Estimated cost: $6,000-9,000

Typical onset: 60,000-120,000 mi

Symptoms: reduced power, frequent active regen cycles, excessive fuel consumption, check engine light with P2463 or P244B codes, strong sulfur smell during regen

Fix: LMM was first-year DPF for Duramax; system clogs with short trips or poor maintenance. Cleaning requires 3-4 hours plus specialized equipment, but filter often needs replacement. Many owners delete emissions equipment (off-road only). OEM DPF replacement: 4-6 hours labor.

Estimated cost: $800-3,500

Typical onset: 80,000-140,000 mi

Symptoms: ticking or tapping noise from engine, check engine light with P0300-series misfire codes, rough idle, loss of power, metal shavings in oil

Fix: AFM lifters collapse, causing cam lobe wear and potential catastrophic failure. Requires lifter replacement, camshaft inspection/replacement, and often valve spring work. 16-22 hours labor. AFM delete kit during repair is wise. Less common than older 5.3L but still happens.

Estimated cost: $2,800-5,500

Typical onset: 70,000-130,000 mi

Symptoms: grinding noise in 4WD, fluid leak from transfer case, hard shifting between 2WD and 4WD, 4WD not engaging

Fix: Internal pump housing wears through case, causing leak and eventual failure. Requires transfer case removal and rebuild or replacement. 8-12 hours labor. Some technicians install upgraded pump assembly during repair.

Estimated cost: $1,800-3,200

Typical onset: 90,000-150,000 mi

Symptoms: whining or howling noise from front end, gear oil leak at pinion seal, vibration during acceleration, grinding in 4WD

Fix: AAM 9.25 front diff sees heavy loads; pinion bearings and seals wear. Requires differential teardown, bearing replacement, new crush sleeve, and setup with dial indicator. 6-9 hours labor if caught early. If run low on oil: complete carrier replacement adds 3-4 hours.

Estimated cost: $1,200-2,400