No hot Air

[Tin Medic]

New core and blower motor. Both heater hoses are getting hot but no hot air. Pulled the bottom hose while running and there is just steam coming out of the water pump. Pump is only 2 months old. Any ideas? This is on my CJ7.

[Stuka]

Is the engine over heating?

[Tin Medic]

It started to last week when I took it off the road. It was blowing water out of the overflow tank and the heater core.

[Stuka]

Then it sounds like there is a good chance the water pump is not working correctly, or the system needs to be bleed. That or maybe the thermostat is not opening when it should.

[carnuck]

The spring from the lower hose may have been sucked into the pump

[HowardT64]

i'd check the thermostat first... cheapest and quickest to check. I
was taught, once you get it out, place it in a pan of water then
out it on the stove. If the unit does not change, its shot.

Otherwise you will see it slowly open

[carnuck]

I replace them if more than 6 months old. Lately I've had 2 dead in the box (made in China) that didn't even open in a pot of boiling water!

[serehill]

Water pump There are no obstructions that should stop water from running out when you remove the hose thermostat or other unless it's corrosion. Strange if you get steam out of it you should get water. I've seen the heater outlet stopped up with rust. if there is no circulation there is no heat. Even a thermostat stuck closed will completely stop up a heat system. the bypass will let that much water flow. It wouldn't hurt to check the t stat but it is not your root cause.

[Tin Medic]

I will be checking the t-stat tonight. Would that keep water from coming out of the pump?

[TUDrewser]

Maybe I missed it, but when you turn the heat on and put the fan on high, do you at least feel air coming out the ducts in the cabin? IOW, the blower is at least pushing air through the ducts, right?

[Tin Medic]

I have plenty of air flow, just not hot. New heater core and blazer motor upgrade.