no problem, let me know what the diagnosis was!

 

Okay, if the top tube is cold and not heating up that means that you don't have circulation of your coolant. (obvious) So yes that means you could have a failed water pump. BUT, have you checked your thermostat? Here's what you do:

1. Put on a pot of water on the stove to boil. Go out to your car and proceed to step 2

2. Unbolt your thermostat housing and take your thermostat out.

3. Take your thermostat and drop it in the water (which should be boiling at this point)

4. Wait a few seconds and watch to see if it opens up. If it opens up quite a bit, it's not your problem. If it opens up just a little bit or not at all, then it's the problem or one of many. Better hope it's one thing! haha

5. Go to Honda and buy a thermostat. Cheap aftermarket ones are just that... cheap! and will fail long before the honda one will. I have one with 135000km on it and it's still good.

Hope that this helps. It's a lot cheaper than a water pump and much easier to fix.

 

if the thermostat stuck in the closed position, you wouldn't have any hot coolant going to the top pipe of the rad
if it stuck open, the car wouldn't get up to operation temp

he has no circulation, hot coolant is only making it to the rad by convection