2004 Chevrolet Silverado 2500HD (LB7 Duramax) — Should You Buy One?
Typical asking price: $12,000–$24,000. There are 2 high-severity known issues you need to know before handing over a check.
Kestrel Take
The first Duramax, the LB7 — emissions-simple, strong, and paired with the excellent Allison automatic. Its one famous flaw is injectors that fail from the inside; a truck that has had the updated injectors done is a genuinely great, simple diesel. One that hasn't is a $3,000 job waiting.
Known Issues for the 2004 Chevrolet Silverado 2500HD (LB7 Duramax)
Ranked by wallet impact. These are documented, recurring problems — not freak accidents.
The original injectors fail internally, causing knocking, white smoke, hard starts, and fuel in the oil. The injectors sit under the valve covers, making the job labor-intensive. Updated injectors largely solve it.
Repair cost range: $3,000-$4,500 for all eight
Salt-state trucks corrode at the cab corners, rockers, bed, and frame.
Repair cost range: Varies; terminal if structural
Water pumps and cooling components wear on a 20-year-old diesel.
Repair cost range: $400-$1,000
The Allison is durable but towing-heavy service intervals matter.
Repair cost range: $400 service to $4,000
Walk-Away Red Flags
- ✗Knocking, white smoke, or fuel smell in the oil — failing injectors
- ✗No injector replacement history at high mileage
- ✗Frame and cab rot
- ✗Deleted/tuned with no documentation
Good Signs
- ✓Updated injectors already installed with receipts
- ✓Rust-free southern truck
- ✓Allison fluid service documented
- ✓Clean maintenance file
Found a specific Chevrolet Silverado 2500HD (LB7 Duramax)?
This page covers what goes wrong on the 2004 Chevrolet Silverado 2500HD (LB7 Duramax) in general. The Kestrel report covers this specific car— the asking price vs. market, the photos, the seller's description, and a BUY / NEGOTIATE / WALK AWAY verdict with a negotiation script.
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Known issues on this page are based on documented owner reports, NHTSA complaints, class-action records, and manufacturer technical service bulletins. Individual vehicles vary. A pre-purchase inspection by a trusted mechanic is always worth doing.
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