hi everyone and thanks for your great help!
here is my question:
i replaced my thermostat last summer with a 180 F Failsafe and everything seemed to be allright.
now i noticed that, starting the engine cold, after 2 minutes idling i get the upper rad hose, the radiator and the lower rad hose warmed.. it's 32 F outside.

is this normal or is my themostat broken?
it's a 88 iroc 350 tpi

thank you

 

Thinking the T-stat is stuck open? You can open your cap and see if the coolant is flowing when its cold. Don't open it while hot of course.
Also is your temp selector on heat or defrost? You should have a valve for the heater core. Coolant will flow through that valve and the heater core also connects to the radiator.

 

heater is (obviously) stuck on defrost and when i did the test temp was set to cold (so no heater core transit i guess). but i have the upper hose ( the big one from the engine to te radiator) warmed too.. bad thermostat?

 

The temp lever, cold ---- hot, only moves a door between the heater core and AC evap. It does not control the flow of coolant. The valve near the right valve cover controls the coolant flow and that valve is controled buy the top lever (off, ac. max, heat, defrost...)
Look under the hood. There will be a small hose on the radiator on the right side. It goes to a pipe that goes to the heater core and a valve. the other end of the heater core goes to the valve and the third hose on the valve goes to the motor.
So with warm coolant flowing through that valve to the heater core and from ther going to the radiator that may be what is warming the hoses.

And I have been out in 40 degree weather and it would only take less than 5 minutes for the temp gauge to touch the 100 mark. Closed or opened, the thermostat is conducting heat so it will warm the coolant in the hose as well.

 

interesting! i'll check asap and let you know.
last test was with temp lever cold and flow lever in off position.

thanks

 

with rad cap open i see i very very small flow.
me and my dad kept touching all hoses to and from the radiator and we finded out that the first getting warm is the upper one (from engine to radator).
bad thermostat?

 

Even with a closed thermostat you will still have a small amount of flow.
But how hot is the hose getting?
Remember, heat rises. And even when a T-stat is closed, that metal will conduct heat to warm the coolant in the hose.

Are you having a cooling or warming problem?

 

cooling system is ok.
completely cold, upper hose takes 2/3 minutes at idle to get to 100 F.
i understand that metal will conduct heat to warm the coolant in the hose but to me it's too much; also because in 4/5 minutes (always at idle) the whole radiator get warm. other hoses stay cold.

 

You can remove the thermostat and test it by placing it on the stove in a pot of boiling water and see if it opens.

 

hey bro my thermostat is new and my temp doesnt go past 100 any ideas how do you prime the system

 

I assume you mean prime and in filling and burping maybe.
The system in these cars are not bad like others. When things are working properly they will burp on their own.

After doing work on my cooling system I would slowly fill the radiator waiting a few minutes as the level gets lower and topping off. I will also squeeze the upper hose to help push air out a few times while I fill.
Then I will close the cap and fill the expansion tank almost to the Full Hot mark and run the car until it warms up and its at the temp where the T-stat should open. Shut it off and let it cool. It will take the extra coolant as needed from the tank and its all good.

I have also seen Mac Tools has a nice funnel for filling cooling systems.
Its a radiator cap with a fitting on it and a large funnel you place onto that fitting. Fill the car through the funnel, start it and have it idle with coolant sitting in the funnel. Once the stat opens it will take coolant from the funnel. If it gets too full there is a plug to put in the funnel so you can remove it with the coolant that is left in the funnel and then cap your system.

 

ok cause it eeld like there is no coolent in the hose at all my radiator is topped off and it still seems like theres no coolent moving into the upper hose

 

Sorry, forgot about this post.
Yes, it was a bad thermostat that stuck open after a few weeks of life.