Diesel Engine Coolant Loss Leak From EGR Cooler - keywords 6.6 compression cool cooler cylinder engine EGR exhaust gas gasket glow glowplug leak LMM plug pressure recirculation smoke valve white

This PI was revised to include the use of Vac N Fill to fill the cooling system. Please discard PIP4135.

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

The customer concern may be coolant loss. During diagnosis the coolant may be found in the combustion chamber.

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. When the EGR cooler is replaced it's very important to be sure all air is purged from the cooling system. Please use the SI procedure for Cooling System Draining and Filling (Vac-N-Fill) if possible.

Note: 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.

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.