2006 Grand Caravan Overheating mystery
3.3L engine, 71,000 miles. Coolant flushed at 50,000 miles, waterpump went bad at 69,000 miles and was replaced.
Everything working great, then it suddenly starts overheating. Gauge shows hot, upper rad. hose is hot to the touch. Heater hoses, lower rad. hose, cap, all cool. Sounded like a typical thermostat stuck closed.
1. Changed thermostat, no difference
2. coolant looks clean, no leaks
3. Oil looks clean
4. Is now at a mechanic. They suspect an airlock, but haven't been able to clear it. They say thermostat is good, and water pump is working.
HELP! My ideas of the problem.
1. Radiator blocked? System looks clean.
2. Water pump works fine at idle, but isn't pumping at driving conditions? Impeller/shaft slipping on a new pump?
3. Blown head gasket? No tailpipe steam, oil and coolant look perfect.
4. An airlock put into the system when I changed the thermostat? That won't clear out?
Any help is greatly appreciated. Trying to get some ideas to help the mechanic.