No heat Still 2003 liberty 3.7L

[onrywayne]

Guys i have watched every youtube read every thing related to this 2003 liberty. It started in june radiator cracked. replaced it then last month son teyed to use heater. No heat so i work on it evey weekend i tryed flushing system with blue devil and heater core started to leak. replaced heater core still cant get heat unless i pump the 3/4 hose on heater core. but eventually the heat in cabin goes from 140° to 80°. I mean heat wont stay flowing to heater core. When i did heater core i checked blend doors work fine also cut hole in hvac box and i can see it working and also tell theres no heat coming from heater core. so we said maybe thermostat. Ok got one from parts store. no luck so order a mopar one from rockauto. no luck tryed flushing more. Also disconnected heater hoses ran water threw there fine ran water threw engine block with heater hose off thought maybe the outlet on the engine block was blocked maybe used screwdriver felt somthing in there but not sure if it was. flushed again with water came out fine. still no heat. so i said well maybe waterpump is wore out. replaced it even though nothing was wrong with the other one. still no heat. when i fill up every time i have it parked at end of driveway slop on ramps with a no spill funnel bleeder ***** open 45min. bubbles stop. after some time but still no flow to heater core. i rev it up 3000rpm 30 seconds let off i can see more bubbles when i give it gas. which im thinking is that a head gasket leak. car doesn't over heat or smoke i can idle all day no problem and i drove it 4hrs straight with out a problem with over heating. so just dont make sense to be a headgasket. I had two other guys look at it they do work on jeeps and other cars alot and they cant seem to figure it out. dont make sense only thing left to replace would be the two heater hoses.i dont loose coolant and car dont over heat. so maybe air stuck in heater core?if so i cant get it out i have idled on ramps with the no spill funnel for 2hrs before. going out rev engine every so often. If i keep reving engine i can get heat to come up slowly but it starts to go away soon as i let of gas. I use a thermometer in the cabin vent to watch the air temp so i can see temp go up then down.Its like im not getting circulation to heater core also which hoses is intake hose to heater core one is 5/8 the other is 3/4

 

[onrywayne]

You may need a air bleed Funnel Set

 

[BeerStop]

i would check the big line, pull it off and hold it to a bucket, does coolant come gushing out ?, also i would pull the core and hook a garden hose to it and see if it is allowing full flow, someone mentioned earlier a cap could be broken off, whichever line goes back from the heater core to the engine is what you need to check for obstructions .
i really havent dug into mine as my heater works but not getting a hot hose when the other one is hot is a sign of blockage.no way 1 heater hose is blazing hot and the other is cool.
there must be a blockage in there, i would check the core.

 

[BeerStop]

also i replaced my radiator , thermostat and water pump and did not need any fancy bleeder equipment. its a miracle my lib didnt **** up as the temp would never go above full and it was empty of coolant before i fixed it.

 

[crz4prez]

I am fighting a plugged heater core, have flushed multiple times. I seem to get new chunks out every time I flush. I believe it may be coming from the engine after I replaced antifreeze with the correct type. I feel you may have a similar issue and are plugging the new core.

 

[Stuffhappens]

parts that have been replaced are heater core old one was 80% blocked. i have installed 2 thermostat first one was from autozone. then i saw on here people saying order a mopar one. so i installed that. radiator was replaced before heater core because it had a leak and we didnt even need heat then so we didnt know heater core was bad yet. then the last thing we replaced was water pump. my next idea is to hook heater hoses together (bypass) heater core and see if i get flow threw hoses. if i do then know its not the engine blocked up. it would be either i bought a bad heatercore or just trapped air.If i dont get flow then not sure how to remove what ever is in engine. also if i didnt get all the old green coolant out how would i go about doing another flush just to be safe. im starting to get worried theat maybe when i put the correct fluid in there maybe it mixed with some green coolant i havent noticed anything. like i said i flushed it pretty good i thought and i have ran water threw system multiple different times looking at flow and replacing parts making sure its not clogged.

When u put in new thermostat did you make sure bleed hole was on tip? Know a lot of people just shove them in and they wont bleed the air off right if not done right. Met one person that actually put in one upside down. Didn't know that was possible. Lol

 

[Phil2020]

@gbennett21

Hi there,
Have the same problem, at first thought it was that I have the same color of Jeep that you have, but here is what I have done:
Mine 2002 Jeep Liberty Ltd Dlx (Dlx means: not just Fully loaded but has the CD-Changer too)

1) Replaced old plenum & heater core with brand new ones
2) Replaced old water pump with brand new one
3) Replaced old thermostat with a "Sport" one, they open faster. (Checked before install)
4) Replaced old coolant reservoir tank with brand new one
5) Replaced ALL heater hoses with brand new ones
6) Brand NEW radiator with brand new one
7) Replaced old coolant with Pres tone ORANGE coolant
8) Replaced old belt tensioner with brand new one, (was there anyway, thought why not)



Still NOT getting Full heat out of vents in car, at best getting 70/80 degrees

1) J.E.E.P. means: "Just empty every pocket"
NB: A/C works amazingly well, thinking of selling this Jeep if cannot get this fixed

 

[LibertyTC]

Prestone coolant NO !! The only correct coolant is Mopar HOAT or Zerex G-05 for our jeeps. See your owners manual.
Prestone or anything other than the correct Hoat coolant does not mix well together, turns to gel and can damage a plastic impeller water pump= flush time!! dealer is best option.
Find a dealer with the pressurized re-circulating coolant machine. Never use tap water in coolant systems, De-mineralized water only.
Sport thermostat? Only use a Mopar thermostat it has the bleed air hole and built in gasket part # 6817 4083 AA
Pressure test the recovery tank @15psi (needs adapters) mopar cap should be 16psi.
If any leak or air is entering the coolant tank/or system it wont pressurize properly.

 

[Duster]

Oh no... so sorry. I had someone make the same mistake as you did on mine.

The orange coolant is wrong and incompatible, prestone or any brand.

Mopar coolant is HOAT coolant. To me it looks red. Some say it looks redorange. And in some overflow bottles (mine) it looks orange. But when you look at it in the black radiator it looks red.

Anyways, you must use Mopar HOAT coolant (reddish) or the Zerex G-05 HOAT formula (kinda golden).

Mixture of the orange coolant formula and HOAT formula causes a reaction. Your small passages are clogged up with stuff that looks like oatmeal.

Mine has a radiator cap on the radiator itself and when I opened it I could see a bunch of oatmeal looking stuff floating in the coolant. When I flushed it was everywhere, and in my case they had only drained and refilled my catch bottle. So it was only mixing at the top of the radiator cap. I didn't know there was an issue until it took out my water pump and seals.

So the starting point is to completely drain it out and see what you find in the coolant. Then start flushing or replacing clogged up parts. Flush several times with water until you get all the **** out and then drain and refill with HOAT.

I think while mine was all apart I just kept sending water through the top of engine until it was coming out clean at the bottom. What a mess.

 

[uss2defiant]

color of antifreeze doesn't matter. it's the type of coolant that matter. I believe way back in the day tjkj2000 mentioned that there was an orange HOAT that he had used in his shop.

 

[Duster]

Yeah but in this case with these symptoms it sound at least pretty likely the issue is from mixing Dexcool or OAT coolant in with HOAT coolant and the two are not compatible. A chemical reaction occurs that will **** your water pump and seals, and it also creates a biproduct like oatmeal in the coolant that plugs stuff up like radiators, heater cores, small passages, etc.

 

[Phil2020]

@gbennett21

FIRST: On your 2003 Jeep, (same on the 2002) looking down on the hoses from the engine compartment: the hose on the LEFT in the COOLANT OUT HOSE, the hose on the RIGHT is the COOLANT IN HOSE. (Can't remember sizes.)

(We thought we'd put up the direction of coolant hoses to your heater core, as none of the previous posters gave you that info, even when you asked them 3 or 4 times.)

Hi there G,
This is a GREAT topic as we have the same problem!

We did ALL the changes you did, even used a Mishimoto racing thermostat, (they kick in at lower HIGH temps, tested in the hot water basin first before install).
We also have 2 Jeeps a blue Jeep like yours and a white one.

All the parts we bought we tried out on the white one first, and when it worked awesome, we transferred those exact same parts into the other Jeep, core, thermostat, rad, plenum c/w heater core, vac hoses, vac pack, vac dash kit, reservoir etc, even the same engine hoses, same problems you've got! Even the pressure test came back great, holds with NO problems!
There must be something we're missing!
We're lucky to have 2 Jeeps we can try and solve problems faster by comparison from one Jeep to the other.

One poster said something about sealing surfaces, but after looking at our notes, ALL sealing surfaces are fine.
Another poster said that there may be a coolant valve, NO such valve exists on any of our Jeeps. No control valve either.

We initially thought that there may have been some idiot that put in GUNK in the reservoir to fix a leaky rad, (we're not 1st owner, we're 2nd) and that stuff is deadly for cooling systems. Possibly, but nah!
Grew up with Barrs, much better fix and it's been around since the 1940's.

But installing a complete system, and taking it out and installing it again in the 2002, and no change we just gave up for the time being.
It's a tricky one for sure, (and a pain in the butt) maybe now we'll take another look.
BTW, (A/C no leaks, Freon, NOT propane, works great! And ALL Plenum doors fully operational)

NOTE: We also noticed, in case you missed this on yours, underneath the outside vent where the wiper blades go, we were told by the dealer's mechanic that there was a filter we have to change. So, we removed both wiper blades, and took off the plastic cowling at the front outside of the Jeep where the wiper blades came off, (be careful taking off the plastic clips), NO filter exists, but was slightly dirty, vacuumed it out, but nothing serious.

Main parts of the heating system:

You must be registered for see images Blower Motor

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Blower Motor Control Module / Resistor

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Climate Control Module

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Heater Air Door Actuator

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Heater Core

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Heater Hose

and lastly the: Ambient Air Temperature Sensor.

*Did you check/change the, "Ambient Air Temperature Sensor?"

Please keep us up to date

 

[crz4prez]

So I have drug my feet long enough, I didn't want to see all the posts about how this isn't properly to fix it, I have functional heat after kind of the same rigmarole. My 2002 3.7 doesn't seem to have enough pressure to circulate through the heater core unless at a higher RPM. I realize what I have done is not keeping within the factories specs or necessarily even fixing the problem, but it is a solution. I ran it all winter and it seemed to work very well. I would have to check what the pump is for I believe it it's possibly a Volkswagen? Found it on Amazon. By adding the circulation pump it has made my heat a lot more consistent. Hopefully the pictures come through.

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[crz4prez]

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[DadOSix]

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Nice work around.
if it works, it works.

i'm thinking you will need to replace your water pump in the near future. Sounds like the impeller is failing.

 

[crz4prez]

Nice work around.
if it works, it works.

i'm thinking you will need to replace your water pump in the near future. Sounds like the impeller is failing.

Previous owner just had it replaced, makes me wonder if it was a cheap one

 

[DadOSix]

Previous owner just had it replaced, makes me wonder if it was a cheap one

I thought i recalled up-thread that you had replaced it. Some of those pumps had plastic impellers that loosen on the shaft.

 

[TimberWolf]

the jeep had green coolant in there when we got it so i flushed it with blue devil flush then went back with the correct fluid. also i havent done pressure test. i do know i have drain and ran water threw this thing at least 10 times thinking somthing was pluged and also every time i replaced somthing seems to flow fine. the last time is when i put a new water pump on. drain the system there was some rust flakes coming out with coolant this time. does anyone know which heater hose is the supply and return. one is 3/4 going back to engine above thermostat then the other is 5/8 going to thermostat housing. This line is also were coolant enters system from the fill tank.

Just wanted to let you know, check the manual for the correct anti-freeze. You could have had the right stuff. Mine 2011 Liberty Sport Manual says HOAT. I attached a pic, maybe it work, but check out what color it says it is, and you can see it says HOAT on there. You just can't mix HOAT with other anti-freezes