Heater blowing warm (not hot) air - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 11-03-2012, 09:41 AM   #1
Newb
 
humpaco's Avatar
 
Join Date: Oct 2012
Location: New Jersey
Posts: 10
Heater blowing warm (not hot) air

Bought a 2002 TJ Wrangler over the summer and love it. Issue is that it is blowing warm (not hot) air from the heater. I read hundreds of posts on this and think I have done/checked everything. Coolant level is fine. Temperature is running at 210 degrees. Both hoses going into the firewall are very hot to the touch. I removed both hoses and flushed the heater core both ways. Does not seem to be any obstructions as water flows freely both ways. Blend door actuator motor is working properly. Removed the actuator motor and manually turned the blend door. I can hear hear it move in both directions so that seems fine as well. Air Cond works fine. Its getting cold here in NJ so trying to fix this issue asap. Any advice? This is driving me crazy. Thanks.

humpaco is offline   Quote Quick Reply
Old 11-03-2012, 10:11 AM   #2
Jeeper
 
Phaeton's Avatar
 
Join Date: Oct 2011
Location: Bend Or
Posts: 62
Seems like you covered everything. Mine does not blow so hot either. If you figure it out please let us know.

__________________
1997 TJ R/C 4" lift, MB Motoring Wheels, 33" tires, SmittyBilt Front and Rear Bumpers. SmittyBilt Rock Sliders, Mile Marker Winch. RR Catback Exhaust.
Phaeton is offline   Quote Quick Reply
Old 11-03-2012, 10:25 AM   #3
Jeeper
 
tallzdatank's Avatar
 
Join Date: Sep 2012
Posts: 1,045
leak in your ducting?
tallzdatank is offline   Quote Quick Reply
Old 11-03-2012, 11:00 AM   #4
Jeeper
 
Join Date: Jun 2012
Location: Southeast, LA
Posts: 16
I had this problem last winter. Previously I had put one of the Autozone thermostats into the Jeep that sticks open if it fails. Replaced it with a conventional one and my problem went away.
z21-i is offline   Quote Quick Reply
Old 11-03-2012, 12:15 PM   #5
Jeeper
 
Join Date: Oct 2011
Posts: 1,606
Quote:
Originally Posted by z21-i View Post
I had this problem last winter. Previously I had put one of the Autozone thermostats into the Jeep that sticks open if it fails. Replaced it with a conventional one and my problem went away.
A temp of 210 contraindicates an open thermostat.
tangofox007 is offline   Quote Quick Reply
Old 11-03-2012, 12:28 PM   #6
572
Jeeper
 
Join Date: Jul 2012
Location: Oklahoma
Posts: 129
Have you tried CLR?

I flushed my heater core and some gunk came out, and the heater is warmer now, but it still doesn't get as hot as I'd like.

I've been thinking about putting a little CLR in the heater core for a while then flush it out real good and see if it helps. I've heard some folks have had good results doing this.
572 is offline   Quote Quick Reply
Old 11-03-2012, 12:56 PM   #7
Jeeper
 
SurfKaster's Avatar
 
Join Date: Mar 2010
Location: St. Augustine FL
Posts: 1,630
PO might have removed the thermostat.
SurfKaster is offline   Quote Quick Reply
Old 11-03-2012, 02:05 PM   #8
Jeeper
 
jeepsrgreat's Avatar
 
Join Date: Aug 2012
Posts: 312
Hope you can find the answer. I'm trying things too. Heater use to make my foot so hot, I couldn't have it on high. Now it's only warm.
__________________
Jeeps are like Lego: Make it any way you want it, break it and start over again.
jeepsrgreat is offline   Quote Quick Reply
Old 11-03-2012, 02:09 PM   #9
Jeeper
 
s14sh3r's Avatar
 
Join Date: Sep 2011
Location: Clayton, OK
Posts: 2,049
Mine's the same way. Runs at 210, flushed the heater core and it flows freely and no junk comes out. Used CLR. Cooling system is clean. Blend door is not stuck. It just doesn't put out much heat. I'm thinking I'll have to replace the core eventually. For some reason it's not transferring heat from the coolant.
s14sh3r is offline   Quote Quick Reply
Old 11-03-2012, 02:37 PM   #10
Jeeper
 
Shelby427's Avatar
 
Join Date: May 2011
Location: Lakeland FL and Hooversville PA
Posts: 2,131
Something I found on ours when I had to replace it, the bottom half of the core was all plugged up on the outside. Dirt/debris had built up, coming in through the fresh air intake. When it got wet it turned to more or less mud and the blower had pushed it into the core fins, blocking any airflow on the bottom half.

Might be worth a shot to pull your blower motor and taking a look inside the housing.
__________________
97 Sahara, 74 Renegade, 72 CJ5, 55 Willy's (the Beast) Boss 302, 6:34 gearing, Bose 901 speakers.
God I miss that Jeep. Forgot the kinda Jeep, 80 SX4.
Shelby427 is offline   Quote Quick Reply
Old 11-03-2012, 05:21 PM   #11
Jeeper
 
Join Date: Oct 2012
Location: Farmington MO.
Posts: 72
Quote:
Originally Posted by Shelby427 View Post
Something I found on ours when I had to replace it, the bottom half of the core was all plugged up on the outside. Dirt/debris had built up, coming in through the fresh air intake. When it got wet it turned to more or less mud and the blower had pushed it into the core fins, blocking any airflow on the bottom half.

Might be worth a shot to pull your blower motor and taking a look inside the housing.

with all he has done , this sounds like it could be the problem.
i am saving this post.
steve67 is offline   Quote Quick Reply
Old 11-03-2012, 05:31 PM   #12
Jeeper
 
Join Date: Oct 2011
Posts: 1,606
Quote:
Originally Posted by Powder Monkey View Post
PO might have removed the thermostat.
And the temp is at 210?
tangofox007 is offline   Quote Quick Reply
Old 11-03-2012, 06:05 PM   #13
Newb
 
humpaco's Avatar
 
Join Date: Oct 2012
Location: New Jersey
Posts: 10
Quote:
Originally Posted by Shelby427 View Post
Something I found on ours when I had to replace it, the bottom half of the core was all plugged up on the outside. Dirt/debris had built up, coming in through the fresh air intake. When it got wet it turned to more or less mud and the blower had pushed it into the core fins, blocking any airflow on the bottom half.
Today I went in and stuck my finger up in the fresh air vent in the firewall that comes down from the hood. I got a bunch of dirt out. Do you think that is related to the lack of hot air? Is there a way to check for blockage without having to remove the core? Thanks for the information/advice.
humpaco is offline   Quote Quick Reply
Old 11-03-2012, 06:20 PM   #14
Jeeper
 
s14sh3r's Avatar
 
Join Date: Sep 2011
Location: Clayton, OK
Posts: 2,049
Quote:
Originally Posted by Shelby427 View Post
Something I found on ours when I had to replace it, the bottom half of the core was all plugged up on the outside. Dirt/debris had built up, coming in through the fresh air intake. When it got wet it turned to more or less mud and the blower had pushed it into the core fins, blocking any airflow on the bottom half.

Might be worth a shot to pull your blower motor and taking a look inside the housing.
Quote:
Originally Posted by humpaco View Post
Today I went in and stuck my finger up in the fresh air vent in the firewall that comes down from the hood. I got a bunch of dirt out. Do you think that is related to the lack of hot air? Is there a way to check for blockage without having to remove the core? Thanks for the information/advice.
You know, I wondered if corrosion inside the core was keeping the heat in, but I never thought about actual dirt inside. Hmmm... now I have something to check. Thanks!
s14sh3r is offline   Quote Quick Reply
Old 11-03-2012, 07:33 PM   #15
Supporting Member

WF Supporting Member
 
scott howard's Avatar
 
Join Date: Dec 2009
Location: wichita falls texas
Posts: 1,035
A easy check to see if your heater core is stopped up with dirt on the outside and not letting the air flow thru it freely to transfer the heat to the ducts of the Jeep is to set it on defrost and temp on cold and feel how much air is flowing . Now switch it to Hot and see if it loses a lot of air flow( it will be a little less just because it has to blow thru the core but it should not be a lot less ) if so your core is clogged with dust and dirt and need cleaned .
The best way is to remove it but if you pull the blower motor and you have a air compressor and a nice long air gun you can sometimes blow it out.
Be careful and not bend the honeycomb closed.
__________________
Scott Howard
940-444-1972
scott howard is offline   Quote Quick Reply
Old 11-03-2012, 07:53 PM   #16
Jeeper
 
s14sh3r's Avatar
 
Join Date: Sep 2011
Location: Clayton, OK
Posts: 2,049
Quote:
Originally Posted by scott howard View Post
A easy check to see if your heater core is stopped up with dirt on the outside and not letting the air flow thru it freely to transfer the heat to the ducts of the Jeep is to set it on defrost and temp on cold and feel how much air is flowing . Now switch it to Hot and see if it loses a lot of air flow( it will be a little less just because it has to blow thru the core but it should not be a lot less ) if so your core is clogged with dust and dirt and need cleaned .
The best way is to remove it but if you pull the blower motor and you have a air compressor and a nice long air gun you can sometimes blow it out.
Be careful and not bend the honeycomb closed.
...and the good tips keep on coming
s14sh3r is offline   Quote Quick Reply
Old 11-03-2012, 09:06 PM   #17
Jeeper
 
s14sh3r's Avatar
 
Join Date: Sep 2011
Location: Clayton, OK
Posts: 2,049
I just tried it and it flows significantly less switched to warm. Like, it flows as much on cool and low than it does on warm and high. I know what I'll be doing first chance I get.
s14sh3r is offline   Quote Quick Reply
Old 11-04-2012, 01:44 AM   #18
Jeeper
 
jeepsrgreat's Avatar
 
Join Date: Aug 2012
Posts: 312
I'll be checking this tomorrow. Hope this tracks down the problem.
__________________
Jeeps are like Lego: Make it any way you want it, break it and start over again.
jeepsrgreat is offline   Quote Quick Reply
Old 11-04-2012, 04:08 AM   #19
Jeeper
 
Fireaxe's Avatar
 
Join Date: Aug 2009
Location: METRO ATL
Posts: 1,252
Subscribed until we get heat!
__________________
United States Coast Guard
Support Search and Rescue...GET LOST!
Fireaxe is offline   Quote Quick Reply
Old 11-04-2012, 07:27 AM   #20
Newb
 
humpaco's Avatar
 
Join Date: Oct 2012
Location: New Jersey
Posts: 10
I'll try the defroster test today but one bit of information I forgot to add in my original post was that I noticed if I have the fan set on the lowest setting there is decent hot air coming out of the vent. But the higher I turn the fan the cooler the air gets. Is that also symptomatic of a blocked/dirty core? Or an issue relating back to a clogged fresh air intake?

I'll break out the air compressor today and see if that makes any difference. I will repost later with results.

Love this forum. You guys are great.
humpaco is offline   Quote Quick Reply
Old 11-04-2012, 01:08 PM   #21
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 33,197
Images: 2
Yep that makes me think the heater core just isn't putting out the heat it should. Did you flush the hoses too or just at the ports on the firewall? Maybe the hoses, though they are hot, just aren't flowing coolant well enough.
__________________
When you have a choice, buy American.

Jerry Bransford is offline   Quote Quick Reply
Old 11-04-2012, 01:31 PM   #22
Jeeper
 
s14sh3r's Avatar
 
Join Date: Sep 2011
Location: Clayton, OK
Posts: 2,049
When I flushed mine, I flushed the hoses as well. I'm getting ready to pull the Jeep up to the shop and pull the blower motor and take a look. I don't know how well I'll be able to see in there, but if there is any debris I'll take a pic and post it.
s14sh3r is offline   Quote Quick Reply
Old 11-04-2012, 02:00 PM   #23
Jeeper
 
div4gold's Avatar
 
Join Date: Feb 2012
Location: WA
Posts: 507
Jerry might have the answer to this: I was wondering if the heater control valve wasn't opening all the way if you would get the symptoms described?
__________________
2006 TJ Unlimited, stock.
div4gold is offline   Quote Quick Reply
Old 11-04-2012, 02:34 PM   #24
Jeeper
 
s14sh3r's Avatar
 
Join Date: Sep 2011
Location: Clayton, OK
Posts: 2,049
Well, here's what I found when I pulled the blower motor:



Here's after I blew it out best I could:



I haven't put it back together yet and there are some other things I need to do before I can run the heater to see if it's improved, but I'm betting there's an improvement because a good 25% of the core wasn't allowing airflow through it. I'll post results later.
s14sh3r is offline   Quote Quick Reply
Old 11-04-2012, 02:37 PM   #25
Jeeper
 
dixau11's Avatar
 
Join Date: Mar 2012
Posts: 542
I was about to go through that whole process, but then realized my heat cable wasn't working, reached down and
Pulled the lever. Boom heat!! I was happy..
__________________
1997 Jeep Wrangler TJ
Zero to sixty? Yes.
dixau11 is offline   Quote Quick Reply
Old 11-04-2012, 04:51 PM   #26
Jeeper
 
s14sh3r's Avatar
 
Join Date: Sep 2011
Location: Clayton, OK
Posts: 2,049
It now gets uncomfortable to hold your hand over the defrost vents. I wish I had a thermometer to check the air temp at the floor vents as per the FSM. I did grab one of the wife's candy thermometers and put it on top of the defrost vent and got 125 degrees. The ambient temp is 70 degrees. The specs are for the air temp at the floor vents with the engine at operating temperature to be 147 degrees. Without a proper thermometer, I won't be able to tell if it's within specs, but it's blowing pretty damned hot, so I'm happy. Now to see how it does in the cold
s14sh3r is offline   Quote Quick Reply
Old 11-04-2012, 05:28 PM   #27
572
Jeeper
 
Join Date: Jul 2012
Location: Oklahoma
Posts: 129
s14sh3r...What year is your Jeep?

I was just wondering if you had to remove your blower motor from under the hood (behind the battery) or from inside the Jeep? I think they changed where you access the blower motor sometime around 01 or 02.

I think I may need to clean my heater core like you did and it looks like you had decent access to the heater core.
572 is offline   Quote Quick Reply
Old 11-04-2012, 06:26 PM   #28
Supporting Member

WF Supporting Member
 
scott howard's Avatar
 
Join Date: Dec 2009
Location: wichita falls texas
Posts: 1,035
This preston flush kit works very well and cost only around 15 dollars.
And the preston radiator flush and cleaner chemical will remove an unbelievable
extra amount of rust and corrosion that a water back flush can not remove and it only cost 6 dollars.
I install these flush kits on all my Jeeps and do a back flush every 3 years.
The whole labor time to install kit and do a flush is 20 minutes.
If you do this and pull the blower motor and clean the outside of your heater core with compressed air you will have heat like when it was new.
__________________
Scott Howard
940-444-1972
scott howard is offline   Quote Quick Reply
Old 11-04-2012, 07:36 PM   #29
Newb
 
humpaco's Avatar
 
Join Date: Oct 2012
Location: New Jersey
Posts: 10
Jerry, I I flushed through the firewall only. Good suggestion about the hoses. Will do that this week.
humpaco is offline   Quote Quick Reply
Old 11-04-2012, 07:46 PM   #30
Newb
 
humpaco's Avatar
 
Join Date: Oct 2012
Location: New Jersey
Posts: 10
Quote:
Originally Posted by scott howard
A easy check to see if your heater core is stopped up with dirt on the outside and not letting the air flow thru it freely to transfer the heat to the ducts of the Jeep is to set it on defrost and temp on cold and feel how much air is flowing . Now switch it to Hot and see if it loses a lot of air flow( it will be a little less just because it has to blow thru the core but it should not be a lot less ) if so your core is clogged with dust and dirt and need cleaned .
The best way is to remove it but if you pull the blower motor and you have a air compressor and a nice long air gun you can sometimes blow it out.
Be careful and not bend the honeycomb closed.
Scott, I get the same airflow through the top vent on hot and cold so it doesn't sound like a clogged/blocked core. (right?)

Also, I removed the blower motor to see if i could gain any kind of access to the core to blow it out with compressed air. I have a 2002 so it is removed from under the dash rather than under the hood behind the battery. Couldn't see or feel the core so couldn't really do too much.

I'm out of ideas at this point. Any other suggestions?

humpaco is offline   Quote Quick Reply
Reply

Tags
heat , heater , not hot , warm air

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Download our Mobile App

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 09:20 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC