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Makes 🢒 Chevrolet 🢒 2004 🢒 Kodiak C-Series Motorhome (Cutaway) C4/C5 🢒 Bulletins 🢒 Turbo Charge Air Cooler Hose Oil Seepage, Or Dislodged On Acceleration - keywords 04 05 06 07 6.6 black boost clamp cool intake LBZ leak LLY low no noise P0299 pipe power smoke surge turbo whistle

Turbo Charge Air Cooler Hose Oil Seepage, Or Dislodged On Acceleration - keywords 04 05 06 07 6.6 black boost clamp cool intake LBZ leak LLY low no noise P0299 pipe power smoke surge turbo whistle

Subject:Turbo Charge Air Cooler Hose Oil Seepage, or Dislodged On Acceleration

Models:2004-2007 Chevrolet Express, Kodiak, Silverado Classic
2004-2007 GMC Savana, Sierra Classic, TopKick
Equipped with the LBZ or LLY 6.6L Diesel Engine


This PI Was Superseded To Include The 2007 Model Year. Please Discard PIP3068C.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Oil seepage from turbo charge air cooler hoses, or charge air cooler hose becomes dislodged during acceleration.

It is possible to have DTC P0299.

  1. Due to the closed PCV system on the 6.6 LLY engine it is normal to have oil residue in the air charge cooler hoses and pipes.
  2. The oil will migrate to the lower areas of the air charge cooler system and may cause customer concerns of oil seepage.
  3. This may also cause the Charge Air Cooler hoses to dislodge when turbo boost is high.

Recommendation/Instructions:
  1. Do a visual inspection of Charge Air Cooler connections and hoses.
  2. Replace Charge Air Cooler hoses, pipes, or clamps if damaged.
  3. Properly clean all oil from Charge Air Cooler pipes and hoses.
  4. Charge Air Cooler hoses and pipes are marked for proper installation. The hoses are marked with ENG, DUCT, or CAC (charge air cooler). The hoses and pipes must installed correctly. The engine side is marked ENG, the duct side (the aluminum pipe) is marked DUCT, and the charge air cooler side is marked CAC.
  5. Apply a very thin coat of sealer part number 97720043 to the Charge Air Cooler hose connections.
  6. Install hose and properly torque charge air cooler hose clamps to 70 lb in/8 nm.
  7. Allow the RTV sealer to dry for 3 to 4 hours. Recheck the Charge Air Cooler for leaks using the appropriate Kent Moore leak tester.

Kent Moore tools are listed below.

   • 

2001-2005 C/K trucks equipped with the 6.6 LB7 and LLY Diesel Engine - Tool Number J-46091.

   • 

2006 C/K trucks equipped with the 6.6 LBZ or LLY Diesel Engine - Tool Number J-46091-5.

   • 

2006 G Van Equipped with the 6.6 LLY Diesel Engine - Tool Number J-46091-10.

There is a new procedure for testing air charge cooler systems. At this time, the Charge Air Cooler Diagnosis (Full System Air Leak Test) can be found in the SI diagnostics for the 2007 model diesel engine vehicles. This full system test can be used on older model vehicles equipped with the Duramax Diesel Engine.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.