I am looking at a new to me 04 Durango, 4.7L a good deal in exceptional condition, except the coolant. oil on stick looks clean. coolant smells normal, no overheating, no other issues. any chance this is normal ? maybe rust? 156,000 mi

 

Time for a coolant power flush and a new thermostat. My 07 is also getting one before winter for a similar reason. The coolant system can work fine for years, mine has since 2007, but it does need maintenance and fluid changes as the fluid ages.