More heat problems

[liberty74]

Hello everyone. I've been having this ongoing problem with my Jeep. It's a 2002 Limited with the 3.7, it has 140000 miles. Searched everywhere and can't seem to find what I'm looking for. The problem started the winter of 2010 with not having very good heat. The radiator was replaced in 2009 because of the infamous crack. The heat worked before and after the radiator install. In the winter of 2010/2011 I noticed it wasn't getting heat so I replaced the thermostat and water pump. Still no heat. Just had the system flushed at the local Jeep dealer. No heat:icon_frown:. Thought maybe the the blend actuator door was possibly goofed up? Also checked the radiator hoses and heater core hoses today. All were hot to the touch after driving 25-30 miles, except the lower radiator hose. Could this indicate a plugged radiator, bad thermostat, or possibly something else. I've looked all over the radiator for leaks and am not seeing any. Everything else looks dry also. Not sure if this is relevant or not but after driving the 25-30 miles, I was able to pull the radiator cap without there being any system pressure. Tried 3 different caps and after running to build system pressure was able to pull all 3 with no problems. Been beating my head against the wall trying to get this fixed and northeast Ohio is getting cold. Thanks for you help.

Jeff

 

[Porkchop]

Lots of ?
Is thermostat closing.
Heater core pluged.
What temp will it get to.
Heater core inlet & outlet temps.
Is the blower motor running.
Whats the gage read on dash.
How long to get to full temp over 190.
Rad fan on hi all the time.
You sure blend door working.
Heater switch on dash.
Sorry need more info as lots of ideas come to mind.
No pressure running cool you would think stat is saying open and not letting it heat up to temp.
Hope this helps you to check a few things and get back with us.

 

[liberty74]

Let's see if I can answer these questions.
1. Not sure if it's opening or closing
2. I pulled the inlet and outlet hoses on the heater core. Ran water through both sides. Seemed to flow through both the in and out free and clean.
3. Temp of the interior of the Jeep oroperating temp of the Jeep?
4. Not sure of the actual temps, but they were hot to the touch.
5. Yes. It runs on all speeds.
6. The gage (once to operating temp) reads in the middle.
7. Usually about 10 mins.
8. The fan only kicks on when the engine gets warm. As to it running on high or low not sure. Just know it does kick on.
9. When the temp control on the dash is moved the temp coming out of the ducts doesn't seem to change. Currently trying to get to this to check this.
10. Is there a way to check the switch? Fan speed works, defrost/floor works, not sure about temp. switch.
It does seem like it could be the t-stat, but thought it would overheat or trow a code if not working properly.
I'll do some more checking. Thanks

Jeff

 

[Porkchop]

Well if the heater core is getting hot and the blower motor is running need to check under the dash sounds like its not letting air across the heater core. I would check the blend door first and if its good check the controls under the radio.
What bothers me is you said no pressure in the rad.
Has it been presure tested and the cap.
Hows the oil have you checked that.
Hows the tans fluid have you checked that if you have an auto trans.
And yes closed stat over heating open stat to long to warm up schould see a mil light.

From tap talk at work sorry.

 

[liberty74]

Well put in a new thermostat just because. Put it back together and the radiator was only getting warm at the top near the inlet, the rest was cold. So new radiator. Pulled the blend door actuator and it's working. Gets warmer than it did since putting in the new radiator. The cap hasn't been pressure tested. Even with the new radiator it doesn't seem to be building alot of pressure. With hood up and when it shuts off you can kinda hear what sounds like the cap releasing pressure but can still pull off without any problem. The oil was just changed. Can the ****** fluid really have an effect on heat? I'll have to go and check that next. Thanks .

Jeff

 

[Porkchop]

Pressure check that cap will help to see if it holds pressure to a set point.
Checking pressure in the rad will help check for leaks in the block the trans cooler or maybe the rad itself. The rad is made to cool as fluid goes through it the stat is what makes it stay at temp to cool it closes to hot it opens and people have put them in cars backwards.
So any coolant in the oil or any coolant in the trans fluid will be from a leak in the rad trans cooler.

 

[DCoxson2003KJ]

From the limited experience I have working with the Libertys I noticed the thermostat is one of the only ones I have installed that is backward from all the other ones. The spring part goes into the block. Is there a remote possibility that it was done in reverse here?

 

[liberty74]

The new t-stat was put in the right way. Before I put it in I called the dealer and asked them for sure which way it went in .

Jeff

 

[Porkchop]

Witch way did they tell you to install the stat?

 

[liberty74]

They said the spring part went into the block.

Jeff

 

[LibertyTC]

When Jeep is cold, remove the reservoir cap, (ensure you are at cold line) and start the KJ and allow the jeep to warm up about 10 minutes, then replace the cap and see if bleeding has made any difference.

 

[liberty74]

well it's been several months and was lucky winter last year wasn't to cold. Still having these problems. Today I took the dash apart to see what I could see. The defrost door/vent door above the blower is working as it should. Wasn't sure how to check to see if the blend door was working so I pulled the actuator off and was able to use a screwdriver to turn the blend door. Started the Jeep up and let it run for about 10/15 mins. got back in and checked the blend door again while running. All the way one way and it is freezing cold, turn the other way and it is still just warm, not hot. I checked the hoses for the heater core and they SEEMED to be ok. I did notice that the air conditioner lines from the drier? were cold. So possibly could it BE the heater core or something with the A/C? Thanks

Jeff

 

[first&lastKJ]

Any pics. of the dash and exact location of the blend door actuator?
What had to be removed to get to the blend door actuator?

I also noticed that the A/C lines were cold and the A/C kept kicking on and off while the heat was on high. It seemed like the air was running at the same time the heat was.

 

[liberty74]

I'll try and get pics tomorrow.

 

[liberty74]

Well buttoned everything back up today. New heater core and all is good now. Get's nice and warm. Must of knocked a hose off somewhere that controls the defrost/floor controller as now I only have defrost. Was curious what the inside of the old heater core looked like, one tube completely plugged and a bunch of other ones corroded up pretty good.

Jeff

 

[first&lastKJ]

Did you have to remove the HVAC unit to get the heater core out?

 

[Billwill]

Well buttoned everything back up today. New heater core and all is good now. Get's nice and warm. Must of knocked a hose off somewhere that controls the defrost/floor controller as now I only have defrost. Was curious what the inside of the old heater core looked like, one tube completely plugged and a bunch of other ones corroded up pretty good.

Jeff

If you are only getting defrost and no floor airflow then you must have knocked off the vacuum hose from the inlet manifold that operates the vanes for re-directing the air flow.:shrug:

 

[dee696]

i have kind of the same problem with my 2002 liberty...

therm is ok
temp is ok
heater core unclog
at least,1 blend door seems ok,not for the other one,and where they are...

can you check my video i made yesterday about it??

i just can get it...where is the problem...???

jeep liberty 2002 heat problem/hvac box issue - YouTube

thanks!