What? A Honda with a problem? Say it isn't so!

If it weren't so new I'd be thinking the hose is getting weak. I'd also be thinking the heater core might be leaking.

Never really knew why, but if you take the cap off and observe, when you rev the engine up, the coolant level will appear to drop. If a hose is too soft, when the cap is on the hose can collapse as you say. I haven't seen this in a long time, but back in the day, there was often a piece of wire coiled up like a spring installed inside the hose to keep that from happening.

I'd be more concerned about the steam coming out the vent. Is there a smell associated with that? Do the windows fog up with the defroster on? Is the floor wet under the carpet on the passenger side? If the answer is yes to any of those questions I'd suspect the heater core is leaking. If not, maybe water or ice was collecting on the evaporator or not draining somehow and getting blown out the vent.

In any case, it's time to take it in to figure out where the coolant went at least, and why it isn't being drawn out of the overflow bottle. That's usually a problem with the cap or hose between the overflow and the cap. The car should still be under warranty. Time to use it.

What he said. If the coolant system develops partial vacuum, the radiator hose will collapse and flatten, like yours did. The problem needs to be fixed, so that you don't overheat your engine, and cause serious(expensive) damage.

Thanks for your input.
Re: Steam from vent while using A/C.
My wife said she did not smell any. So, I don't think it was coolant. Maybe just condensation evaporating...
I won't take a chance and I will have dealer take a look at the cooling system.

Would think if the hose was collapsed, and the radiator water level was low, and you had water in the overflow tank... over flow isn't flowing back into the radiator with suction the like the way things are supposed to work because the radiator cap is bad or the dip hose is clogged pretty darn good or busted between the overflow tank and cap.

As the engine cools after shut-down, the coolant contracts. Normally, reserve fluid is drawn back into the system from the overflow bottle, and yes, a slight vacuum is formed to do this. If the return path has too much restriction, the vacuum increases and can collaspe a hose. However, a proper hose should have enough body stiffness to withstand the ususal amount of vacuum and should be able to draw fluid back into the system. Deteriorated hoses may collaspe. Another cause is that the hose was not the proper one, or good one, in the first place and did not have body stiffeners within it. Sometimes, the bottom radiator hose may have a spring-like coil of wire in its body; The upper one may, or may not have such stiffeners.

Places where restrictions may occur in the return line (from the overflow bottle)

o Wrong radiator cap, or one with a stuck or plugged valve.

o Collasping hose from the radiator to the overflow bottle.

o Gunk in the bottom of the overflow bottle getting sucked over the return opening.

o Interference on the hose going from the coolant system to the overflow bottle, like a mounting clamp pinching this hose.

I presume this is a new problem that has developed lately, therefore its a good bet that both (upper and lower) radiator hoses should be relaced. And while these are off, its a good idea to change the thermostat too.

I wonder if there are any dealers with designer radiators they can install for the car, like apart from the stock ones that they use for repairs and servicing. I like to make my car unique, even if it is under the hood.

No wonder this forum is deserted.