i got a 2004 chevy blazer with over heating problems. there are no apparent leaks, the system is holding pressure. the water pump is circulating water fan clutch works. but i cant go an hr or so without the truck overheating. im currently traveling so every hundred miles or so i gotta let the truck cool down before filling it with a half gallon or more of coolant. at my wits end. flushed the radiator n block 3 times, new radiator cap and thermostat. i donno what to do.
If you see no coolant leaks yet you are adding a half gallon of coolant every hundred miles indicates the coolant is going somewhere. It may be a small enough external leak that the coolant is burning off before it reaches the ground. Or, it is a small head gasket or intake manifold gasket leak. If you need help pinpointing the coolant leak, consider YourMechanic. One of our mobile experts can come to your home to service your vehicle.