'07 Jeep Liberty (KJ) - No Heat

[killjoy]

Hi Guys,

I'm hoping we have a Chrysler mechanic that works on this type of stuff, or someone else who's experienced the same problem. My sister's 2007 Jeep Liberty has been back to the shop 4x now to fix this problem... still not fixed... and the shop is now telling her not to bring it back, they have no clue what's wrong. She's $1000 into this mess..

2007 Jeep Liberty 3.7L 4x4 Sport

Short Story
- Car has no heat.
- You can feel a little heat with the blower on low. Nothing but cold air when on medium or high.
- Local mechanic has replaced the following w/o fixing the issue:

• heater core
• radiator
• actuator
• water pump

- Shop is now telling her they have no clue what's wrong.

Long Story
- Heater core blew last summer - car overheated briefly. Towed to our local mechanic where he replaced the heater core. Everything seemed fine.
- Two months later, my sister smelled radiator fluid. Took it back the same shop... radiator empty, so they replaced the radiator and everything seemed fine.
- Winter comes, no heat. Take it back to the shop....
- Shop tries fixing by first replacing the actuator... then, the water pump.
- Shop is now telling her they're out of ideas... take it to the dealer.

Any ideas what could be wrong? Anything I can check? The mechanic has had the dash/IP removed so many times, I'm almost afraid something mechanically is wrong on the heater controls.

 

[moparman]

Maybe it's low on coolant with an air pocket in the heater core.

 

[richar43]

try looking at the blower motor resistor, as well. One other thing, I know on my wifes van, my kids were complaining of no rear heat, and all i had to do was the diagnostic- recalibration steps with the ignition key, and it reset the rear actuator. I'm not saying this may be the issue, but it is food for thought. As someone else stated, possibly a air pocket in the heater core. Also try this....
If your system is working properly and thermostat will open as it is supposed to.

Run the engine with open cooling cap. keep it at 2000 rpm, keep collecting pan under car fluid will come out.

Watch temperature closely do not let it overheat, fluid will be coming out together with air in the system, add coolant if goes down, when heat comes refill and close the system.

 

[rockymountain]

What type of coolant did your shop use?

 

[killjoy]

Saw the truck myself last night. I think I've isolated the problem to inside the cabin.

- Truck comes up to & maintains normal operating temp (verified by IP temp gauge)
- Both of the heater hoses (send & return) between the water pump & heater core are very hot - roughly operating temp. Both hoses are roughly the same temp. (blockage seems unlikely)
- With the controls on max heat & lowest speed blower, she gets moderately warm air... but low volume. Warm enough that it's evident that the heater core is adding some heat.
- With the controls on max heat & medium or high blower, the air is barely luke warm... actually feels barely above cabin temp.
- With the controls on lowest speed blower, if I move the temp setting from hot to cold, there is a very noticeable difference in air temp. Cold is much colder than hot when the blower is on low.


Rockymountain: Not sure - I'd have to ask.

richar43: Blower seems to be working fine in term of air volume per speed setting.

Your recalibration idea was mentioned to me by someone else. They thought that whenever something was changed in the HVAC box, a scanner had to be hooked up to the car to recalibrate the doors. I'm hoping this is it... but was also hoping to find someone else w. the same problem and find out what they've done to fix it.

morparman: I doubt it. She's been driving the car for 3 weeks now... I would think that air pocket would work itself out by now. Also, both heater lines from the WP to the HC are blistering hot. Seems that the HC is getting tons of heat, but the cabin HVAC air flow isn't getting directed through the core.

 

[rockymountain]

I'd say the temp control/actuator is bad. I would try the actuator if I had to start guessing. It is controlled electrically.

 

[killjoy]

- Local mechanic has replaced the following w/o fixing the issue:

• heater core
• radiator
• actuator
• water pump

I'd say the temp control/actuator is bad. I would try the actuator if I had to start guessing. It is controlled electrically.

See above - mechanic just replaced the actuator trying to fix the problem. I'm just not sure if a scanner or some other reflash needs to be done as well.

 

[rockymountain]

See above - mechanic just replaced the actuator trying to fix the problem. I'm just not sure if a scanner or some other reflash needs to be done as well.

possibly the blend door was broke when they replaced that? :shrug:

 

[killjoy]

possibly the blend door was broke when they replaced that? :shrug:

Yea, that's the conclusion I'm coming to as well.... blend door broke when they were in there fixing the heater core or something else. Trying to find a junkyard that has a complete heater box assembly before ripping into her truck. Any ideas what years heater boxes are identical? Are all of the 2002 - 2007 HVAC parts identical?

 

[Digger873]

I have the exact same problem with an 02 Liberty.
With this problem I am starting to notice a trend. In each case I have read about this particular problem in the liberty the radiator has been replaced.

Mine developed a pinhole leak in the plastic tank and I replaced it.
I have replaced the thermostat, and the radiator cap, I verified the heater core is not blocked and the heater core hoses are both hot 112 F going in and 98 F coming out on a 25F day.

I have tore apart the dash and verified the blend doors seem to be functioning properly and replaced the blend door actuator. Mine is an older model so the calibration is manual and I have calibrated it twice.
I have bled the system and checked operating pressure of system when hot. About 8# at 2000 rpms
The only thing I have not done is replace the temperature switch itself. Still it doesn't seem to work properly.

One thing I have noticed is the lower radiator hose will be cold even when the engine is at operating temp, and I have checked it after driving 30+ miles and it will still be cold. The strange thing is when I have checked the lower hose and it is warm as it should be the air coming from the heater is warmer.

When I changed the blend door actuator I had to unhook the battery (which would reset the PC), and when I first ran it after putting it back together it seemed to work, although not quite as hot as it should be. After a few days my wife started telling me it wasn't getting hot and she was freezing again. So I drive it and sure enough it is barely warm again.

I am really frustrated and the dealers around here only seem to know how to say "bring it in and we will look at it" But when I ask what they are going to do that I haven't they cant seem to answer me.

I guess what I am going to do next is pull the codes and check the temp switch to see if it is working.:shrug:

I am feeling a new ride in the very near future, and it wont be a Chrysler product

Oh yeah one more thing, you cannot replace the heater core or disassemble the heater box and blend doors with out the ability to unhook the evap coil for the AC system. You can replace the actuator and move the blend doors but you cant take out the blend doors without removing the entire heater box.