Exhaust Odor During DPF Regeneration - keywords 6.6 align alignment clamp diesel down engine leak LMM pipe regen shield soot turbo turbocharger
| Subject: | Exhaust Odor During DPF Regeneration |
| Models: | 2007-2008 Chevrolet Express, Kodiak, Silverado |
| 2007-2008 GMC Savana, Sierra, Topkick |
| Equipped with the 6.6L Diesel Engine RPO code LMM |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A dealer may encounter a customer concern of exhaust odor during a DPF (Diesel Particulate Filter) regeneration.
A leak at the turbocharger exhaust pipe may induce an exhaust odor that is noticed during a DPF regeneration.
Recommendation/Instructions:
Inspect for leakage at the turbo outlet to turbocharger exhaust pipe (down pipe) connection. Complete the current SI diagnostic for Charge Air Cooler Diagnosis (Full System Air Leak Test). Exhaust soot accumulation on the inside of the turbocharger exhaust pipe heat shield may also be noticed. If a leak at turbocharger exhaust pipe has been verified, inspect the exhaust pipe for misalignment. Inspection may reveal misalignment at the turbocharger exhaust pipe retaining bracket.
Align or adjust the turbo exhaust pipe as needed. If the exhaust pipe continues to leak, replacement of the turbocharger exhaust pipe may be necessary. Replacement of the retaining bracket may also be necessary if it was damaged by the pipe misalignment.
Make repairs as needed and evaluate the customer concern.
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.
