Roman,
For what its worth.... My 99 rodeo LS was overheating during a trip to and from Utah. Nursed it there and back, but even after replacing the thermostat in Utah and taking the radiator off to have it checked & flushed still it overheated! Finally had to take it to a professional who had everything checked! Turns out my motor had blown a head gasket... a small area between layers of the gasket. Compression from one of the cylinders was messing up my coolant system! Motor warranty covered almost all of it thank God! Just my two cents worth Good Luck!

Glassen