Would a hot upper radiator hose and a cold lower one mean that the thermostat is stuck closed? Any ideas? I've been trying to bleed the system, too. Thanks guys.

 

I think thats fine. Since the coolant going in your rad is hot and the coolant that is coming out is significantly cooler.

 

it is a possibility. how long was the car running?

 

i'm having the same problem but i think its the water pump. i won't fine out until tomorrow when i get the part from honda.

 

I'd start with a thermostat.

 

sounds like thermostat. And if steam starts to come out the radiator top, then its defenitly your thermostat. I just recently took out my thermostat because it was stuck closed. Damn autozone stuff. It was like a month old.
manny

 

yeahhh thermostat. The top hose will also be hard, the bottom not.

Remember thermo wont open till car is hot. So let the engine idle for a good 10min and make sure the fan comes on too before you make the assumption its overheating.

-Eric

 

The car runs for at least 10 minutes and the bottom hose is totally cold. Not even warm. The fan doesn't come on either. It worked before the engine change and all of the connectors are hooked up. Maybe I just didn't let it run long enough for the fan to come on. I'll change the thermostat tonight and see what that does.

 

Take the thermostat out and boil it in water..if it stays shut it's bad..

 

Since thermostats are fairly cheap, I think I'll just get a new one and see if that corrects the flow problem. If anyone else has some ideas on what might be causing the hot upper and cold lower hoses please chime in. I really would have thought that the lower one would haved been the one that would have been hot and the upper cold if the thermostat was stuck closed????? Not the other way around. Guess that shows my limited mechanical understanding of these babies!

 

Well I figured it out! The rad hose coming from the bottom of the rad is fairly long and goes uphill for a foot plus and there was a huge air bubble in it. Squeezed the air out of it and eventually all of the air in the system bled out of the bleeder and walla, heat! Now I have no more excuses to drive it for the first time since the self performed first time engine replacement. Hope it don't blow up on me too far from the house! Thanks everyone for your ideas and suggestions.

 

dbailey, I had to make an account real quick to just say Thankyou I’m having same issues when going to work this morning and most suggest a thermostat, in which case doesn’t always work. It’s because the lower hose has air!!!

just did a clutch on the car, I assume maybe from 3 days of being jacked up along with having to change a small hose that went to my TB, air became trapped In the system. Squeezed the lower hose a few and wala! I watched the bubble come out the from rad and she warmed up no problems.


PRE EXSISTING CONDITION, no heat in cabin, irrational random overheating, top hose hot bottom hose ice cold.

thanks again👌🏻