'07 Jeep Liberty - No Heat (reward offered!!!!)

K

Killjoy

Forum Member
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.


If not, any recommended shop/mechanic to take this thing to? Service at the Troy Motor Mall Jeep has been terrible lately.
 
1BADAIR said:
hoses hot in and out?
Click to expand...
I believe so. I'm headed over there after she gets off work to look at the truck myself for the 1st time.

1BADAIR said:
did they vac the system?
Click to expand...
They claimed to. Also, she's been driving the vehicle for 2-3 weeks now since the last time in the shop. Can't believe an air bubble/lock wouldn't have worked itself out by now.

I'm thinking a vacuum line... or something with the controls themselves.
 
Killjoy said:
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.


If not, any recommended shop/mechanic to take this thing to? Service at the Troy Motor Mall Jeep has been terrible lately.
Click to expand...
Sounds stupid but check the oil also...
 
Did they recalibrate the HVAC doors with a scan tool after they did they heater core install ?

If not, that will cuase this problem.

you can mail the case of beer to

5711 elizabeth lake road
waterford michigan 48327

From the service manual

OPERATION

The blend door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated three-wire lead and connector of the instrument panel wire harness. The blend door actuator can move the blend-air door in two directions. A potentiometer within the actuator allows the A/C-heater control to know the exact position of the blend-air door at all times.

The blend door actuator can be diagnosed using a scan tool.

The blend door actuator cannot be adjusted or repaired and must be replaced if found inoperative or damaged.
Click to expand...


The heating-A/C system uses a reversible, 12-volt direct current (DC) servo motor which mechanically positions the blend-air door. The blend door actuator (1) is located on the top of the HVAC housing.

The blend door actuator is contained within a black molded plastic housing with an integral wire connector receptacle (2) and three integral mounting tabs (3) that allow the actuator to be secured to the HVAC housing. The blend door actuator also has an output shaft with splines that connects it to the linkage that drives the blend-air door. The blend door actuator requires mechanical indexing to the blend door linkage.
Click to expand...

These doors must be recalibrated after any hvac box work. if not they typically fail to function.If your in the area let me know. takes a few minutes.
 
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From chrysler dealer connect. Service info.
DESCRIPTION


The heating-A/C system uses two vacuum operated mode door actuators (1) to control the movement of the mode-air doors within the HVAC housing.

When vacuum is supplied by the A/C-heater control to the vacuum connector (3) on one side of the defrost/floor actuator or the panel door actuator, the actuator rod is pulled into the actuator, which moves the mode door lever and mode-air door in one direction. When vacuum is supplied by the A/C-heater control to the other side of the actuator, the rod moves the mode-air door in the other direction.

The mode door actuators are retained to the HVAC housing by an integral mounting provision (2) and can be accessed for service from under the driver side of the instrument panel.

The mode door actuators cannot be adjusted or repaired must be replaced if found inoperative or damaged.

The heating-A/C system uses a reversible, 12-volt direct current (DC) servo motor which mechanically positions the blend-air door. The blend door actuator (1) is located on the top of the HVAC housing.

TEMPERATURE CONTROL
If the heater outlet air temperature cannot be adjusted with the temperature control on the A/C-heater control, the following could require service:

Inoperative A/C-heater control.
Inoperative blend door actuator.
Inoperative, obstructed or improperly installed blend-air door.
Inoperative related wiring harness or connectors.
Improper engine coolant temperature.


The blend door actuator is contained within a black molded plastic housing with an integral wire connector receptacle (2) and three integral mounting tabs (3) that allow the actuator to be secured to the HVAC housing. The blend door actuator also has an output shaft with splines that connects it to the linkage that drives the blend-air door. The blend door actuator requires mechanical indexing to the blend door linkage.
 
The control head on this car will self calabrate, All you have to do is reset the control head. Easy way to do this is disconnect the battery or remove the IOD" ignition off draw fuse" wait 10 min and re connect. aside from this listen for doors moving in the housing, Check coolant flow.
 
If you really need. Pm me and I will give you a link and way to get service info, Direct from Chrysler. No I will not post live i do not want to change paswords everyday thank you.
 
Before performing the following tests, refer to Group 7 - Cooling for the procedures to check the engine coolant level and flow, engine coolant reserve/recovery system operation, accessory drive belt condition and tension, radiator air flow and the fan drive operation.

WARNING: Do not remove radiator cap when engine is hot. Failure to follow this instruction may result in serious injury.


If vehicle has been run recently, wait 15 minutes before removing the radiator cap. Place a rag over the cap and turn it to the first safety stop. Allow pressure to escape through the overflow tube. When the system pressure stabilizes, remove the cap completely.



MAXIMUM HEATER OUTPUT
Engine coolant is delivered to the heater core through two heater hoses. With the engine idling at normal operating temperature, set the temperature control to the full hot position, the mode control to the floor position, and the blower motor control to the highest speed position. Using a test thermometer, check the temperature of the air being discharged at the front floor outlets. Compare the test thermometer reading to the Heater Temperature Reference chart.



HEATER TEMPERATURE REFERENCE
Ambient Air Temperature 16° C
(60° F) 21° C
(70° F) 26° C
(80° F) 32° C
(90° F)
Minimum Air Temperature at Floor Outlet 52° C
(125° F) 56° C
(133° F) 59° C
(139° F) 62° C
(144° F)

If the heater outlet air temperature is below the minimum specification, refer to Group 7 - Cooling. Both of the heater hoses should be hot to the touch. The coolant return heater hose should be slightly cooler than the coolant supply heater hose. If the return hose is much cooler than the supply hose, locate and repair the engine coolant flow obstruction in the cooling system. Refer to Group 7 - Cooling for more information.



OBSTRUCTED COOLANT FLOW
Possible locations or causes of obstructed coolant flow are as follows:

Inoperative water pump.
Inoperative thermostat.
Pinched or kinked heater hoses.
Improper heater hose routing.
Plugged heater hoses or supply and return ports at the cooling system connections.
Plugged heater core.
If proper coolant flow through the cooling system is verified, and heater outlet air temperature is low, a mechanical problem may exist.



MECHANICAL PROBLEMS
Possible causes of insufficient heat due to mechanical problems are as follows:

Obstructed cowl air intake.
Obstructed heater system outlets.
Inoperative engine thermostat.
Inoperative blower motor system.
Inoperative A/C-heater control.
Inoperative blend door actuator.
Inoperative, obstructed or improperly installed blend-air door.


TEMPERATURE CONTROL
If the heater outlet air temperature cannot be adjusted with the temperature control on the A/C-heater control, the following could require service:

Inoperative A/C-heater control.
Inoperative blend door actuator.
Inoperative, obstructed or improperly installed blend-air door.
Inoperative related wiring harness or connectors.
Improper engine coolant temperature.
 
Thanks for the info guys. As soon as I get a chance to see the truck myself, I'll let you know. First thing I want to do is make sure the heater hoses are hot, that way I can confirm it's a problem inside the cabin.

Sean - thanks, I may be PM/calling!
 
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.

Sean said:
Did they recalibrate the HVAC doors with a scan tool after they did they heater core install ?

If not, that will cuase this problem.

...

From the service manual

These doors must be recalibrated after any hvac box work. if not they typically fail to function.If your in the area let me know. takes a few minutes.
Click to expand...

Sean: Does the symptoms I describe match what you would expect if they didn't calibrate the doors?

The mechanic who did the work says he did not use a scan tool, but followed the manual procedures as outlined in the service manual. :shrug:


ReiKo said:
Sounds stupid but check the oil also...
Click to expand...
Checked the oil - it was fine in terms of level and consistency. She had an oil change about 2 months ago... oil was still very clean and @ the full mark.



So, in summary, sounds like a problem somewhere in the HVAC box/control area. I really don't want to rip apart the dash/IP!!!! I'm wondering if the blend doors aren't adjusted correctly... and with low air volume, the air stream happens to be moving partially through the heater core... but bypassing it (for the most part) with higher flow.
 
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does the vent output volume seem to adequatley correspond with the blower speed setting? not like a restricted air inlet path?
 
dave89iroc said:
does the vent output volume seem to adequatley correspond with the blower speed setting? not like a restricted air inlet path?
Click to expand...

Yes, air volume seems to be fine & corresponds to the blower speed level. Medium and High blows a lot more air than low, but the air is cold.

I also changed the controls from top vents, to bottom vents, to windshield defrost. Air flow goes in the right places and plenty of volume, just no heat on medium or high. A little heat on low...
 
I suspect the HVAC box has suffered damage and the door can't get through a calibration sweep rendering it Inoperative.
 
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