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!
PITA thermostat issue
- Thread starter Stuntmanmike77
- Start date
Mounce
Member
I'm not sure but I do know these systems flow opposite of others you're probably more familiar with if that helps.
Flows opposite? I don't know much about these engines, how does it flow and how would i know if the thermostat is opening? Shouldn't the lower hose be hot also?
Mounce
Member
Ah okay, thought your issue was that the hot hose was opposite from what you thought it should have been.
The two hoses will always be different temps. Gotta figure in the fact that the coolant has traveled through the radiator and is returning at a lower temp than it entered.
The two hoses will always be different temps. Gotta figure in the fact that the coolant has traveled through the radiator and is returning at a lower temp than it entered.
Blckshdw
Moderator
Yes, the bottom hose should always be cooler than the top. It would be helpful if you had a scanner, so you could either monitor the coolant temp to see when you get up to around 195 when the thermostat should open.
It's a little late now for your new one, but 1 way people sometimes test their thermostat, is to put it in boiling water, and watch for the valve to pop open.
It's a little late now for your new one, but 1 way people sometimes test their thermostat, is to put it in boiling water, and watch for the valve to pop open.
Yeah, dropped the ball on that one, should have tested it first. I'll keep an eye on it till i get it to a shop. Thanks.
