Hi. New here from trailvoy trying to get some answers. So, I finally replaced the thermostat in my 03 trailblazer and lower hose. Filled it up then ran it. After 10-15 minutes or so upper hose got hot and coolant started rising up as it should. Put a new cap on it but after about 20 min. I had good heat upper hose nice and hot lower hose, luke warm? Please tell me I didn't install a faulty t-stat. Hopefully did not cause any damage to the engine since my gauges dont work either!