Upper radiator hose hot, bottom is cold......why?
 

What does this mean? I just replaced the thermo from the honda dealer, and did my best to bleed the system of air, yet the damn upper hose is really hot and the bottom is cold? My fan is not coming on either, but I suspect its because the thermo is closed..Help!

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

motor is gsr https://honda-tech.com/forums/images...s/emsmilep.gif

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

bump

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

well the fan should come on if it sits at an idle for acouple minutes unless your thermostat isn't hooked up correctly. and as for the heater hoses. i had that problem with my crx, and i just figured that it was b/c i had air in that bottom line. let it cool down some.... and take off your radiator cap. then start the car, the air bubbles will raise to the top and release. don't worry it isn't going to overflow when you start it. i did this last night to my car. if it is hot when you take it off it will also have some pressure so when you turn it push down real hard and slowly ease up.. you'll hear the pressure releasing..that will also get some of the air out. good luck

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

Because your radiator is doing it's job. https://honda-tech.com/forums/images/smilies/emthup.gif The upper hose is the coolant that has been heated by the engine and the lower is the coolant that has been cooled by the radiator. If your temp sensor is fine don't worry about it.

Re: Upper radiator hose hot, bottom is cold......why? (Spade)
 

Um no. The lower hose WILL get hot as soon as the thermostat opens up. You guys all must have felt the hose prior the thermo opening up... http://images.honda-tech.com/set1//smile/emcrook.gif

Re: Upper radiator hose hot, bottom is cold......why? (Mikey)
 

Haven't had a cooling problem yet. Hose is cold. Not ice cold just cold. Even with the radiator fan on....hose feels cool to touch.

Re: Upper radiator hose hot, bottom is cold......why? (Spade)
 

is the lower hose hard or soft?

Re: Upper radiator hose hot, bottom is cold......why? (pennies_hatchie)
 

Hard. My upper is soft but, that's cause it's getting up there in age.

Re: Upper radiator hose hot, bottom is cold......why? (Spade)
 

hmm. The lower is still supposed to be warm. It should not be cold, unless you have a huge radiator and a really fast fan. If the radiator cooled off the water that much...your thermostat would be opening and closing all day long, instead of slowly fluctuating as it should.

But if you're not having a problem, shouldn't worry about it https://honda-tech.com/forums/images/smilies/emthup.gif

Re: Upper radiator hose hot, bottom is cold......why? (Emerica)
 

Well, it is overheating. The upper is boiling hot(soft) and the bottom is cold and hard. Thermo did not open up once.. So I just took the thermo out, bottom hose got very warm but the damn fan will not turn on? WTF! My ect switch is fine so I am thinking maybe the fan motor is blown? Also my battery just died https://honda-tech.com/forums/images/smilies/emsad.gif

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

This is my third damn thermo from the dealer and none of them are opening up.

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

sucks too cause I have a date tonight and can't even pick up the damn girl now https://honda-tech.com/forums/images/smilies/mad.gif


[Modified by Halo, 5:02 PM 2/28/2003]

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

I know alot of people that have had this same damn problem. All you can do is keep going back until you finally get one that works properly.

I'm definitely not looking foward to replacing mine when it goes bad... https://honda-tech.com/forums/images...es/emdgust.gif

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

hey spade i like your quote. the b16 is a really weak motor

Re: Upper radiator hose hot, bottom is cold......why? (streetdreams02)
 

how common is it to blow your fan motor?

Re: Upper radiator hose hot, bottom is cold......why? (streetdreams02)
 

but to answer your q? just test them before u install them put the thremo in hot water if it opens up then it works, but as far as your fan check the connection make sure it is connected or hooked up and check the ground

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

Well today I installed a new ect switch and thermo the lower hose is getting warmer(1 problem solved) yet the fan still does not go on. I tested the fan and it is working properly. Does anybody know why the fan is not turning on?

Re: Upper radiator hose hot, bottom is cold......why? (Halo)
 

for starters the thermostat has nothing to do with the fan because the thermostat is not electrical and does not control the fan. and as for the fan..i think it may not be turning on because it may not be hot enough. Drive for a bout 10 miles than pull over and let the car idle..check the fan again...if its still not working then take it in...but is your car still over heating? and oh yeah..both hoses are suppose to be warm. Top is always going to be warm, bottom will only be warm when the thermostat opens. I bet your thermostat is fine..u just had to drive around for a little bit. Or you could have installed it backwards i was told this can be done.

Khoi