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2003 Chevrolet Silverado 2500LT Duramax

The LB7 + Allison combo is basically a diesel legend.

Phil R. · Billings, MTSubmitted Sep 2, 20246.6L Duramax LB7 Diesel (V8)

Documented Miles

344,000

on the odometer

Reliability Score

87/100

community rating

Est. Total Maintenance

$41,200

lifetime spend

Est. Savings vs. New

$30,800

vs. buying new

Engine

6.6L Duramax LB7 Diesel (V8)

Allison 1000 6-Speed

Drivetrain

4WD

2003 model year

The Duramax LB7 paired with the Allison 1000 transmission is one of the most respected diesel combinations ever put in a pickup. Phil's done two injector sets — the LB7's known weakness — and kept everything else stock.

Known Issues

We don't sugarcoat. Here's what to watch for — and what to fix before it becomes a problem.

WatchFix PromptlyDeal Breaker

LB7 Injector Failure

Fix Promptly

The LB7 injectors are internally cracked by design — they fail from the inside out. It will happen. Budget $2,000–$4,500 for a set. GM extended the warranty to 7yr/200k on some VINs. Do all 8 at once when you go in.

Typical cost:$2,000–$4,500 (all 8)
When: Typically 100,000–200,000 miles