Radiator Replacement in Service - keywords 3.5 3.5L 3.9 3.9L coolant cooling drain engine flush guage heat hot LZ LZ9 LZE over petcock temperature

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

After radiator replacement, on initial start, a dry radiator will cause coolant prime to be lost as the thermostat opens, then overheating may quickly follow. This is due to the outlet-side fill neck utilized on the LZ series engines.

Typically 0.6-0.7 liters (.64-.74 quarts) of coolant remain in the radiator even after the petcock is opened and the cooling system is drained. This is enough coolant to prevent coolant prime not to become lost.

Prime replacement radiators with at least 0.5-0.75 liters (.5-.8 quarts) of coolant mix when installing new or dry radiators on any vehicle using the LZ series 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.