2002 CHEVROLET SILVERADO 2500HD

Typical onset: 80,000-150,000 mi

Symptoms: white smoke on startup or acceleration, rough idle getting progressively worse, fuel in crankcase oil (dilution), hard starting when cold, significant power loss

Fix: All eight injectors must be replaced simultaneously (under-valve-cover design requires cab removal or cab lift for proper access). Budget 16-22 hours labor for cab-off method. Always replace return line seals and flush fuel system. This is THE issue that kills LB7 resale.

Estimated cost: $4,500-7,000

Typical onset: 100,000-180,000 mi

Symptoms: transmission fluid dripping from radiator area, low fluid warnings, slipping between gears, brownish coolant in overflow tank (internal cooler failure)

Fix: External lines rust through at clips and bends. If internal cooler fails inside radiator, entire cooling system and transmission need flushing. External line repair is 1-2 hours, internal failure adds radiator replacement and system flushes (4-6 hours total).

Estimated cost: $300-1,200

Typical onset: 120,000-200,000 mi

Symptoms: no-start condition with cranking, intermittent stalling at operating temperature, loss of power under load, fuel gauge erratic or inaccurate, whining noise from tank area before failure

Fix: In-tank pump assembly replacement requires dropping fuel tank (2-3 hours on 2WD, add 1 hour for 4WD). Always replace fuel filter and strainer sock simultaneously. Early-life failures rare; this is a wear-out item.

Estimated cost: $600-900

Typical onset: 80,000-150,000 mi

Symptoms: clunk when shifting from park to drive or reverse, vibration at idle in gear, visible sagging of transmission tailhousing, driveline vibration at highway speeds

Fix: Rubber mount deteriorates from heat and oil exposure, especially on diesels with higher torque. Replacement is straightforward: support transmission, unbolt crossmember, swap mount (1.5-2 hours). Inspect crossmember for cracks while you're there.

Estimated cost: $250-400

Typical onset: 150,000-250,000 mi

Symptoms: white smoke from exhaust, coolant loss with no visible leaks, overheating under load, oil contamination in coolant or vice versa, misfires on specific cylinders

Fix: Big-block replacement is labor-intensive: 12-16 hours for both heads. Often find cracked heads on high-mileage examples; budget for machining or replacement. Check for intake manifold gasket leaks simultaneously. Not common, but expensive when it happens.

Estimated cost: $2,800-4,500

Typical onset: 60,000-120,000 mi

Symptoms: service 4WD message on dash, grinding noise when engaging 4WD, inability to shift into or out of 4WD, 4WD indicator flashing, front differential not engaging

Fix: Thermal actuator on transfer case seizes or encoder motor on transfer case fails. Actuator replacement is 1.5-2 hours; encoder motor 2-3 hours (requires partial transfer case disassembly). Often accelerated by water intrusion from road spray.

Estimated cost: $400-800

Typical onset: 100,000-180,000 mi

Symptoms: excessive play in steering wheel (more than 2 inches), wandering on highway requiring constant correction, clunking when turning at low speeds, fluid leaking from sector shaft seal

Fix: Heavy-duty use accelerates wear. Adjustment procedure can tighten temporarily but typically needs full replacement by this mileage. Box swap is 2-3 hours; alignment required afterward. Inspect pitman and idler arms simultaneously.

Estimated cost: $600-1,100