No heat while idling

[birddog777]

I have a jeep liberty 2010, 3.7. I changed thermostat, flushed radiator and heater core. Put in coolant. I get heat as It wasn't putting out heat before. But now it only heats while driving on the road. It doesn't throw out heat while idling. What do you think is the problem? I read here it could be water pump. But wasn't sure about that. Has has anyone else experienced something similiar and what was the fix?

 

[DadOSix]

I have a jeep liberty 2010, 3.7. I changed thermostat, flushed radiator and heater core. Put in coolant. I get heat as It wasn't putting out heat before. But now it only heats while driving on the road. It doesn't throw out heat while idling. What do you think is the problem? I read here it could be water pump. But wasn't sure about that. Has has anyone else experienced something similiar and what was the fix?

Couple things -
Did you use the Mopar thermostat, and get it installed correctly, with the air bleed in the right direction?

Assuming you did and used the HOAT / G05 coolant, I would be thinking water pump all day. The impellers get eaten up or break away from the shaft.

 

[birddog777]

Okay maybe I will have to take a look at the water pump then. Thanks! Cheers

 

[jack roykirk]

I'm sorry to hear that you have this issue because you may not want to hear this. I don't want to put a scare into and here's hoping it's not the case but but do you smell coolant? Monitor your coolant level and see if it goes down. It may be imperceptible at first. I had that same issue last winter but I could smell coolant and it turned out to be my heater core. I replaced in July. Replacing it was a nightmare as you have to pull the whole dash. There's some half-assed videos on youtube on how to do it. It's not for the faint of heart because there are a bazilion screws.

I don't even want to tell you what it would cost to have it replaced by a professional.

 

[birddog777]

I'm sorry to hear that you have this issue because you may not want to hear this. I don't want to put a scare into and here's hoping it's not the case but but do you smell coolant? Monitor your coolant level and see if it goes down. It may be imperceptible at first. I had that same issue last winter but I could smell coolant and it turned out to be my heater core. I replaced in July. Replacing it was a nightmare as you have to pull the whole dash. There's some half-assed videos on youtube on how to do it. It's not for the faint of heart because there are a bazilion screws.

I don't even want to tell you what it would cost to have it replaced by a professional.

Hi no I don't smell any coolant. It heats up good. And doesn't overheat. I suspect it is the water pump as I hear sound coming from that area where the water pump is. Haven't changed it yet but I will.

 

[jack roykirk]

Good luck! I hope that's all it is. I wouldn't wish changing a heater core on anyone after what I went through.

 

[murdoc]

Possible the fluid is just low, or has an air pocket?

 

[birddog777]

Possible the fluid is just low, or has an air pocket?

Possible I was just checking that as well. Put in over half a jug of coolant few days ago. Will see if that helps. I thought I had filled it up. When I changed the coolant. It's not leaking anywhere.

 

[murdoc]

You might have had an air pocket that finally worked itself out. I'd open up the radiator cap (not overflow) if possible. When it's cool of course. And check. Had a similar situation on my wife's mazda and it turned out to just be low coolant. Hopefully it's just an easy fix for you.

 

[mako538]

Also check condition of the belt. I have a 2007 liberty that ran hot at idle (it did throw heat, so a bit opposite of your issue). I thought it was the water pump issue too. but also ordered a belt as the current one didnt look great. old water pump impellars looked fine when i replaced it. so i think the new belt was the fix. (replaced both plus thermostat at same time, so no 100% sure). talk about overkill! but running at right temp now.

 

[birddog777]

Well I changed the water pump couple months ago. Filled it with coolant as much as it could take. Still only put out heat when driving down the highway. Not when idling. I'm wondering if there's a blockage in the vents or is the vent door not fully opening? Where is the vent door located?

 

[murdoc]

I wonder, after you're driving and the heat works, and you park in your driveway, before you turn off the engine, does it still blow hot while you're idling?

Must be a blockage somewhere. Heater core? Radiator? T-Stat? I dunno

 

[birddog777]

I wonder, after you're driving and the heat works, and you park in your driveway, before you turn off the engine, does it still blow hot while you're idling?

Must be a blockage somewhere. Heater core? Radiator? T-Stat? I dunno

No it doesn't blow hot when I park or idling. Just air. I flushed out the core and radiator though. Changed thermostat. Water pump. But then it could be blocked somewhere in the hoses maybe? I'm stumped.

 

[MsRandiCook]

Thermostat or pump. Also concider hose collapse!

 

[KJowner]

Sounds like an air lock in the heater matrix.

 

[MsRandiCook]

W O W, the matrix! I never though of that! Very Kewl!

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