Duramax Diesel Coolant Loss - keywords 6.6 compression coll cooler cylinder engine EGR exhaust gas gasket glow glowplug leak LMM plug pressure recirculation smoke valve white
| Subject: | Duramax Diesel Coolant Loss |
| Models: | 2007 Chevrolet Express, Kodiak, Silverado |
| 2007 GMC Savana, Sierra, Topkick |
| Equipped with the 6.6 diesel engine RPO code LMM |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
The customer concern may be coolant loss, excessive pressure found in the cooling system, or coolant found in the combustion chamber.
Recommendation/Instructions:
Complete the current SI diagnostic for any trouble code or symptom found. If coolant loss has been verified, and a cooling system pressure test was to show coolant leaking into a combustion chamber, inspect for a leaking EGR cooler. Inspect the outlet side of the cooler, and the inlet side of the cooler for leaks.
If coolant has been found in a combustion chamber, remove the glowplugs and rotate the engine over by hand to purge any remaining coolant out of the cylinders.
Replace the EGR cooler as needed, and evaluate the repairs.
Note: Running the engine without coolant flowing to the EGR cooler may result in cooler damage. Please do not run the engine with the coolant hoses disconnected.
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.
