A customer may experience a coolant loss on a 2007 Express, Kodiak, Silverado, Savana, Sierra or Topkick equipped with a 6.6L diesel engine (RPO LMM). During diagnosis, coolant may be found in the combustion chamber.
Follow SI diagnostics for any diagnostic code or symptom found. If coolant loss is verified and a cooling system pressure test shows coolant leaking into a combustion chamber, inspect for a leaking EGR cooler. Inspect the inlet and outlet sides of the cooler for leaks.
If coolant is found in a combustion chamber, remove the glow plugs and rotate the engine by hand to purge remaining coolant out of the cylinders.
Replace the EGR cooler as needed. When the EGR cooler is replaced, be sure all air is purged from the cooling system. Use the SI procedure for Cooling System Draining and Filling (Vac-N-Fill) if possible.
TIP: Running the engine without coolant flowing to the EGR cooler may result in cooler damage. Do not run the engine with the coolant hoses disconnected.
- Thanks to Don Langer
Follow SI diagnostics for any diagnostic code or symptom found. If coolant loss is verified and a cooling system pressure test shows coolant leaking into a combustion chamber, inspect for a leaking EGR cooler. Inspect the inlet and outlet sides of the cooler for leaks.
If coolant is found in a combustion chamber, remove the glow plugs and rotate the engine by hand to purge remaining coolant out of the cylinders.
Replace the EGR cooler as needed. When the EGR cooler is replaced, be sure all air is purged from the cooling system. Use the SI procedure for Cooling System Draining and Filling (Vac-N-Fill) if possible.
TIP: Running the engine without coolant flowing to the EGR cooler may result in cooler damage. Do not run the engine with the coolant hoses disconnected.
- Thanks to Don Langer
Leave a comment