My bottom radiator hose stays cool, while the top one gets really hot. I guess the thermostat not opening up? What kind of problems could this cause if I run my car like this?

Thanks,

Matt

 

If your thermostat doesn't open, the car will overheat, which can lead to many other things, like blown headgasket, cracked engine blocked...

 

Right -- so can anyone figure why my car doesn't overheat? I dont know if the thermo is opening or not, but bottom radiator hose is cool, even after a 2 hr trip on highway; yet, my engine temp stays well in the normal range...

 

well isnt the top one the outlet and the bottom one is the inlet (return)
anyway after your car is at operating temp, what does the temp guage say? do you have a CEL?

 

Temp gauge stays right in the middle -- right in the normal temp range.

sorry -- what's a CEL?

 

hmm well if it isnt over heating then i dont think it's your thermostat, how is the car running?
and a CEL is check engine light.

 

Both hoses will be hot after any two hour drive unless you're driving inside of snow. The only reason your lower hose would be cold is if the thermostat wasn't opening or there was some kind of clog just past it which is allowing the fan switch to turn on due to the passage of coolant, but it's not going all the way through. Normally you would need coolant passing the thermostat to reach the switch to tell the fans to turn on. There is a chance that the thermostat is opening up just enough to let just a lil bit of coolant through which is hitting the switching and somehow not making the hose get hot. I would guess that your coolant temperature switches are not working right, they are saying you're not overheating when really you are, OR you are in such a cold area that you really aren't overheating even though you're thermostat is stuck closed.