top one is hot, bottom one cold . is it a new thermostat?

 

bottom one is catching air when u drive. top would be hot after being on for a long period of time.

 

car is just idleing not driving.

 

is ur car over heating? after being idle for about 15-20 min?

 

no, but there is a little steam coming out under the radiator cap temp gauge is normal

 

when you drive it what happens.... same thing?


either the thermostat isnt getting hot enough to let coolant through or its stuck that way, you have to push the car to find out

 

it sounds like the thermostat
stuck closed

 

Replace it

 

^

if u have steam coming out of ur cap, u might wanna replace that next if the problem continue after u change out the thermostat

 

the cap is prolly leaking.. its supposed to steam, the steam is what pressurizes the radiator and causes the fluid to go into the overflow bottle which is why theres a lb rating for every system. the top hose is hot and bottom is cold because the top hose gets the hot water from the engine when the thermostat is opened, the bottom one is the fluid comming from the radiator that has been cooled by the radiator and the fans, then the fluid goes into the block cooling it down and getting hot by the time it goes thru the block and comes back out the top radiator hose. if both were hot you wouldnt be cooling anything and your engine would overheat.. the thermostat is working fine, but it sounds like eather your radiator cap is not all the way tight or its just leaking. or you checked the fluid level and some spilled out on to the radiator and is steaming...

 

^couldn't put it better myself.

 

to the loose/leaky cap.

 

thanks