Heater Blows Warm, Not Hot
Asked by JimKaiser Dec 05, 2019 at 07:35 PM about the 2011 Jeep Liberty Limited 4WD
Question type: Maintenance & Repair
So my wifes 2011 Jeep Liberty started only
blowing warm air, not hot like before.
So I checked the coolant level and her reservoir
tank was empty. The engine wasn't overheating so
I added coolant to the reservoir tank. This had no
change to the temp of air blowing.
So, I checked the heater core hoses running
through the fire wall. One was super hot, the other
was hot but not as hot as the other. I let the vehicle
cool and checked the electric heat gate under the
dash to make sure it was all the way open for heat
and it was. Once cool I flushed the heater core. It
wasn't real grimy but made sure it flushed clear
both ways. Hooked the hoses back up and took it
for a drive.
Now, the heat blows warm at idle but heats up
when the engine is revved or I accelerate while
driving. I think the issue is either the thermostat or
the water pump. Water pump makes most since to
me as the fluid had to leak somewhere but I have
not noticed any loss of reservoir fluid since I
started digging into this. I do see drips but that
could be from me being a clumpy oaf and spilling
coolant all over. If anyone can help point me in the
right direction or knows the problem I'd really
appreciate any and all comments.
11 Answers
If you are getting poor water circulation I would first purge air out of the cooling system. If that does not do it the water pump impeller may be worn out.
I hadn't thought of an air pocket. Whats the best way to purge air out of the system?
I did look for leaks but me spilling I'm not certain where it's leaking from. I didn't notice some wet grime around where the hoses connect to the water pump housing.
Good place to start,you can rent a radiator pressure tester from your local parts store.
Fill the reservoir, leave the lid off and squeeze the top hose like you're pumping it. It will suck water into the system and relieve any air bubbles. In the mean time check your oil for signs of water and keep an eye on the level of that reservoir. I'm also leaning towards water pump issues.
The way D Patric explained the bleeding of the cooling system is incorrect.
Then Why don't you tell him the correct way of doing it !
Ok so, this thing is running me in circles. I found the leak, it was where the heater core hoses attach to the engine. I replaced those and used better hose clamps. My oil is fine, not watery and right where it was at the last oil change. Over the weekend I changed the water pump, thermostat and cabin air filters. Filled brandnew Chrysler specific coolant and bleed the system with the bleeder screw (on the top radiator hose connection to the engine i found o. YouTube) and by pulling it up on my ramps and opening the radiator cap and reservoir tank. I seriously doubt I have air in the system after that. Now after all that, the heat blows very hot on passenger side and simi-warm on the drivers side. It takes a very long time for the engine to warm up and does not blow hot on either side until the engine is up to operating temperature. Does anybody know where I should look next. Heatercore? I made sure the heat blend door actuator is working. Is there anything else that controls the temp? I really could use some help so if anyone has ideas please let me know. Thank you.
Chrysler was good for heater core issues, you can try removing both hoses and back flushing the core to see if any scale comes out or a small bore-a-scope to try to look inside the core it's self.If a lot of scale does come out fill it back up bleed it again and see if the condition changed.
