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Recipe - Duramax 6.6L V8 Turbo Diesel (GM HD, LB7-LMM 2001-2010)

Specific Fix build

Reliability tier: aggregated - verify before ordering, see /disclosure/

EGR cooler service (EGR cooler clogging / failure (LB7-LMM)): the Duramax has carried cooled EGR since the LB7 (catalog-verified 97288793 for 2002-2004) and the coolers clog with carbon and eventually leak - the LLY-era heat reputation makes cooler health the first check on heat complaints. Catalog route: generation-correct cooler (LB7 97288793 / LBZ 97358507 / LMM 98034351) and the EGR valve (LLY 97303761, LBZ/LMM 98025695) when the valve side fails with it.

Parts

• Duramax LB7 EGR Cooler (OEM) - the catalog-verified LB7-era cooler (2002-2004 window) (qty 1)
• Duramax LBZ EGR Cooler (OEM) - LBZ cooler (2006-2007); the LLY-window cooler PN is an honest gap so far (qty 1)
• Duramax LMM EGR Cooler (OEM) - LMM cooler (2007-2010); MY2007 build-date caveat (qty 1)
• Duramax LLY EGR Valve (OEM) - LLY EGR valve (qty 1)
• Duramax LBZ/LMM EGR Valve (OEM) - LBZ/LMM EGR valve (2006-2010) (qty 1)

Install order

1. confirm the cooler (flow/pressure test) before radiator conclusions
2. verify generation by VIN at the 2004/2007 switches
3. replace cooler and/or valve per findings
4. service the cooling system fully after the job (this is a coolant-circuit component)

Expected outcome

EGR flow restored, no coolant loss into exhaust or degas, heat complaints resolved

Do not

• do not block, delete or defeat the EGR system - it is retained emissions hardware; this resource documents servicing it only
• do not condemn the cooler on heat complaints without a flow/pressure test
• do not reuse the cooler gaskets - catalog gaskets are cheap next to a come-back

Parts budget

About $300-$780 in parts. It depends on what the diagnosis finds; each option below is what you buy together. Prices marked "at Dave's" are Dave's Auto Center's, the same as in his store; the others are approximate prices from OEM and maker catalogs, rounded (a manufacturer's list price can run higher). Parts only, no labor.

• about $780: Duramax LB7 EGR Cooler (OEM) (about $780)
• about $370: Duramax LBZ EGR Cooler (OEM) (about $370)
• about $590: Duramax LMM EGR Cooler (OEM) (about $590)
• about $300: Duramax LLY EGR Valve (OEM) (about $300)
• about $380: Duramax LBZ/LMM EGR Valve (OEM) (about $380)

DIY or shop: Shop: cooler R&R means the intake and coolant circuit come apart - shop territory.