[reedo11]

Hi all, my 2009 Compass Limited has a heating problem. It seems that when the outside temperature gets to be below 40 degrees F, the heater will only put out luke-warm air, and it never gets hot. The coolant temperature is consistently lower than it should be, sits around 3/8 on the temp gauge. I've already replaced the thermostat twice, and can confirm that the current thermostat is not stuck open. The radiator fans are also not spinning at startup, so I believe the fans are not the issue either. I currently have a piece of cardboard zip-tied to the grille to stop air flow to the radiator to make it run hotter (that only seems to help a little bit).

Could it be incorrect coolant? A bad sensor? I really don't know what's wrong, and it's getting to be very frustrating, being that I live in an area that gets very cold in the winter months (down to -20F sometimes!). Any information helps .

 

[Jasmine]

Yeah. -20F here this morning. The World Engine in the first gen Compass has two thermostats. Did you change them both?

 

[Labrador Cab]

Did you check the Actuator from the Airflap ?

 

[reedo11]

Yeah. -20F here this morning. The World Engine in the first gen Compass has two thermostats. Did you change them both?

Are both the thermostats contained in the same thermostat housing? Because this could be a possible cause as I do not recall replacing both, just one of them at least.

 

[Jasmine]

I've not changed them myself, nor have I had either fail. As you may know, the 2.0 and 2.4 World Engine was used in many vehicles across the Chrysler line and beyond, so I'm guessing this info may be the same for a Compass as for a Dodge. I got this from the Dodge Caliber forum: Why two thermostats?

"The primary thermostat is located on the front of the water plenum in the thermostat housing/coolant inlet. The thermostat has an air bleed vent located on its flange. The air bleed vent (1) and the locator dimple on thermostat seal provide for proper positioning of thermostat in inlet housing. The secondary thermostat is located in the cylinder head under the water plenum."

I found the same info for a Chrysler on fixya.com: SOLVED: Are there two thermostats for a 2012 Chrysler 200 - Fixya

 

[BooMan 62]

Interesting.

 

[Need More Power]

Some cars require a air bleed procedure for the coolant system.

 

[reedo11]

I had a thought recently about what might be wrong. Its summer now and there is still very little heat, especially through the defroster and the passenger side vents. The car hasn't had a cabin air filter since I've owned it so I'm wondering if maybe something has clogged up. Both thermostats and housing has been replaced, heater core is hot to the touch on both inlet and outlet hoses, and the blend door works properly. I'm out of any other ideas at this point and am starting to think that the HVAC system in this car might just be horribly designed.

 

[Jasmine]

Are you getting airflow out of the ducts? If so, you should be getting some heat out of the ducts. If no airflow, then the a/c shouldn't be working either. I wonder if your a/c is stuck on, running against your heater?

 

[reedo11]

Are you getting airflow out of the ducts? If so, you should be getting some heat out of the ducts. If no airflow, then the a/c shouldn't be working either. I wonder if your a/c is stuck on, running against your heater?

I am getting good airflow. I recently tried reversing airflow through the heater core by using a leaf blower on the vents, and haven't noticed a significant difference. It's 60 degrees out now, and am getting decent heat out of the vents, except for defrost. When I set the controls to defrost, the AC compressor turns on and heat blows out, for only about 10 seconds. After that, the heat goes cold. I'm wondering if maybe there is a blockage somewhere else or if there is an issue with the AC system. I really want to have this fixed before winter, but I fear that taking this to a mechanic will be very expensive.

 

[reedo11]

And I should note: the AC system works just fine for cool air.

 

[Jasmine]

Maybe you've got air in the cooling system. That would give you hot air sometimes but not at other times, i.e., you get heat when the coolant gets into the heater core, but no heat when there's air in there. The a/c would still run fine because the coolant is irrelevant to the a/c system.

PS, low coolant can also create hot-spots in the engine where there's only air and no coolant. That can lead to bi-i-ig problems.

 

[Pawel8111]

I have the same issue lack of heat and it’s only 64 degrees by me.
i have change both of the thermostats on the body housing Tested the some sensors and no luck
2019 there was a recall for the catholic converter. This is my fathers car so I don’t really know when the issue started as he don’t drive the car much as you can tell from the mileage Anything will help, any advice

 

[asakaze]

I'm getting lukewarm front middle vents and passenger side, vents left and below the dashboard are fine actually it could help in winter switching the zone to windows/underneath only... but the basic problem is, if heat is uneven or mild, a heater core clogged....

Google "Chrysler heater core problem" seems it's a big issue after some years.

So, anyone here done a heater core flush before?
Is there any clogs dissolvent that could mix with coolant?
Heater core replacement means removing the entire dash which is PITA.

 

[Pawel8111]

I did a in heater core flash and change thermostats. Still having the same issue

 

[asakaze]

I've meant by yourself?
How difficult it was, accessible the drain vent or just some lower hose down?
I've got Liqui Moly 3320 Radiator Cleaner. Thinking to drain the old fluid first, fill the system with water add cleaner, leave it running for a half hour, rinse then put the new Mopar coolant.

I've seen no leaks, the cap is fine, hoses probably due to replacement as never been replaced but both hoses leading to the cabin/radiator core are hot. Probably just the old fluid and somewhere clogged.
How to prevent the air getting in? I'm thinking no bleeding but to leave the fluid tank open while engine running for another half an hour for bubbles to get out.
Any advices who done it before?
thanks