Heating Issues, Weird Problem - JeepForum.com
Reply
 
LinkBack Thread Tools
post #1 of 24 Old 11-19-2011, 12:41 PM Thread Starter
-BeNt-
Registered User
1998 TJ Wrangler 
 
Join Date: Jan 2008
Location: Scottsboro
Posts: 280
Heating Issues, Weird Problem

Hey guys, I've search on this for over a month. In the mornings I crank up the jeep, it reaches 210 on the dot after running for a bit, never over heats, fan speed on slow I have nice hot heat.

However if I turn the fan on medium to high settings it blows hot for a few minutes then gets as cold as if the jeep wasn't warmed up. At first I thought this was a heater core issue. I flushed it out a few months back, some gunk did come out but it flowed extremely freely.

Now I keep reading about the heat not working on different settings being the switch or the resistors. However my fan blows on all settings just fine, the heat just doesn't come out on the medium to high settings. Once the air goes cold if I put the fan back on low after a few minutes the heat returns.

It's almost the same symptoms you get with too low of fluid however it does it rather you have throttle on or not. One thing I did notice was the return line coming from the heater core doesn't seem to be getting hot. (Top line hot, bottom line cool enough to touch) So basically like the H/C is clogged.

I'm at a complete lose with this one guys, shy of just tearing it all completely down one part at a time till it works again, hopefully someone here can save me some time / money / aggravation / or my sanity.

Thanks ahead of time.

-BeNt- is offline  
Sponsored Links
Advertisement
 
post #2 of 24 Old 11-20-2011, 02:46 PM Thread Starter
-BeNt-
Registered User
1998 TJ Wrangler 
 
Join Date: Jan 2008
Location: Scottsboro
Posts: 280
Nobody? Any help would be appreciated guys. Bump bump.
-BeNt- is offline  
post #3 of 24 Old 11-20-2011, 04:34 PM
Rubi4MyMrs
Registered User
 
Rubi4MyMrs's Avatar
2005 LJ Wrangler 
 
Join Date: Mar 2011
Location: Trails of
Posts: 4,505
It does sound like the H/C is clogged or there is some kind of restriction. Try flushing it again even with plain water. Flush it both ways (back flushing) including though the hoses. See how well the water flows out as you flush it. Maybe some more of that gunk is now loose in there.
Rubi4MyMrs is offline  
 
post #4 of 24 Old 11-20-2011, 04:44 PM Thread Starter
-BeNt-
Registered User
1998 TJ Wrangler 
 
Join Date: Jan 2008
Location: Scottsboro
Posts: 280
I'll check the vacum lines again. However all the functions work correctly. A/C works just fine heat works fine, though not as hot as it used to be, in all setting except the top two blower notches which make it ultimately turn cold.

Would a thermostat even give me an issue like this if it was stuck in some weird position? From the look of things there is a side channel that feeds the heater core anyways so it shouldn't matter what the thermostat is doing right?

Guess sometime this week I'll probably go ahead and do another flush on the heater core. Is it possible it's already got in bad shape again from just a few months back? The reason I flushed it last time was because of this problem and nothing seemed to change.

Thanks guys I'll check everything out this week and see what I come up with. Anyone have a good suggestion on the easiest / fastest / best way to flush this thing?
-BeNt- is offline  
post #5 of 24 Old 11-20-2011, 05:10 PM
Rubi4MyMrs
Registered User
 
Rubi4MyMrs's Avatar
2005 LJ Wrangler 
 
Join Date: Mar 2011
Location: Trails of
Posts: 4,505
The vacuum controls the flaps & is not related to fan speed.
The return hose not being hot is the key symptom.
You defiantly have a flow problem. Remove both heater hoses from the engine end. Attach a garden hose to the end of one of the hoses. You can find a garden hose fitting intended for a quick disconnect fittings at hardware stores or Home Depot. Attach it to the G hose & push the other end into the heater hose & clamp it with a hose clamp. Turn the water on slowly & see how the water flows out of the other hose. Reverse the process to back flush the system. As you turn up the water pressure you should be able to see the out flow increase accordingly. If you don't, there is still a restriction in the H/C. Depending on what you find you may need a new H/C but at least that is how to test it & hopefully get it opened up.

One affect the thermostat has is to help cause back pressure in the system (restriction) to increase the flow through the heater. The other is if it sticks open the heater won't heat because the engine isn't hot either. You say the engine comes up to temp so there is a thermostat in there & it is not stuck.
Rubi4MyMrs is offline  
post #6 of 24 Old 11-20-2011, 08:41 PM Thread Starter
-BeNt-
Registered User
1998 TJ Wrangler 
 
Join Date: Jan 2008
Location: Scottsboro
Posts: 280
Rbui4MyMrs ok so basically if that thermostat is messed up one way of the other the engine temps would be all screwed up regardless. If that's the case it isn't the thermostat then. It warms up around 210 and sets there. Never stays cool or overheats. Checked vacuum lines today as well as ensuring the heating controls functioned correctly everything there seems fine as well.

So I suppose the next trick will be a reflush on my heater core. I don't think I did a reverse flush last time on it. The heat didn't return last time to it either, well it did for a short while when I was trail riding and worked for about another day or so but then never again. The more I think about it the more I'm starting to think it was what I originally thought it was, the heater core.

Thanks guys for the help, I'll take a trip to Home Depot and see if I can find a hose spout that would fit into that hosing. What is the size of that hosing? 5/8"? (It'll probably be Thursday before I can get back on it now unfortunately and it rained all day today...grr, the Jeep gods aren't liking me right now.)
-BeNt- is offline  
post #7 of 24 Old 12-10-2011, 05:58 PM Thread Starter
-BeNt-
Registered User
1998 TJ Wrangler 
 
Join Date: Jan 2008
Location: Scottsboro
Posts: 280
OK guys finally got around to it, work has had me busy. Anyways, reverse flushed and regular flushed the entire system, and the heat core separately. Now I have no heat at all, versus a little bit of heat?!

The engine does heat to 210, doesn't over heat at all. Everything seems normal. My input line to the heater core is still not getting hot. It got dark before I could move along to the next step. However I went and picked up a thermostat and gasket tonight. Going to try that in the morning.

Surely this is it right? Seems like the only thing left that could be a flow problem with it. I checked the control panel to make sure it was indeed swapping over and it seems to be working correctly. These 30-40 degree mornings are really starting to get to me.

Thanks for the help so far! Is there anything else in the system that could be causing this issue? It seems to me the thermostat / heatcore would be the only things that could be blocking it. Thanks again!

*Edit*
Just a quick update, going to get started early tomorrow after finding this thread: http://www.wranglerforum.com/f5/heat...hot-89993.html

Maybe it's the water pump as well, never even crossed my mind since it doesn't overheat, guess this is now a possibility.....crap.
-BeNt- is offline  
post #8 of 24 Old 12-11-2011, 01:13 AM
Rubi4MyMrs
Registered User
 
Rubi4MyMrs's Avatar
2005 LJ Wrangler 
 
Join Date: Mar 2011
Location: Trails of
Posts: 4,505
That is very interesting. That guy never had overheating! Hard to believe but possible, I guess. Let us know what you find.
Rubi4MyMrs is offline  
post #9 of 24 Old 12-11-2011, 01:18 AM
DallastheJeeper
Registered User
 
DallastheJeeper's Avatar
2006 LJ Wrangler 
 
Join Date: Jun 2010
Location: Viroqua
Posts: 603
Have you checked the thermostat?

__________________
|^^^^^^^^^^^^^^^\ ||__
|.......PBR BEER TRUCK.... ||""\_____\
|____________________/||__/----|
|(@)(@)"""""""""""|(@) (@)***|(@)

#5-06 Salvage Rebuild LJ
Metalcloak Bumper, Overline fenders and Corner guards.
3.5" Sus Lift
1'' Body lift and engine lift

#4-98 TJ Sahara RIP :(
#3-42 GPW Project. Currently on hold Sand blasted the body and it was held together by screen and bondo so new Tub needed
#2-88 Comanche Currently getting a frame off rebuild and a 4bt.
#1-1994 Power Wheels Wrangler
DallastheJeeper is offline  
post #10 of 24 Old 12-11-2011, 09:46 AM
chucktoons
Registered User
2004 TJ Wrangler 
 
Join Date: Apr 2010
Location: Alabama
Posts: 19
Feel the heater hoses to make sure they are hot. If you have heat there but not in the jeep, the problem is in the heater blend door control.
chucktoons is offline  
post #11 of 24 Old 12-12-2011, 08:11 AM Thread Starter
-BeNt-
Registered User
1998 TJ Wrangler 
 
Join Date: Jan 2008
Location: Scottsboro
Posts: 280
Ok update, the problem is solved. So short break down here. I had a heating issue where I would get a little bit of heat but when I would turn the fan on high it would blow cold. I reverse flushed the entire cooling system as well as the heater core separately. Some gunk came out but not really enough to matter.

I cranked and tested, no heat. So I swapped out the thermostat, cranked and tested, still no change. And then, just like the thread I posted up previously, I changed the water pump. I now have heat. This was the weirdest way I've ever had heat do in a vehicle. I still don't understand how it wasn't overheating. Especially considering the condition of the water pump.

I also found out this thing had the original thermostat and water pump in it when it was manufactured in May of 1997. Simply amazing the about of years this lasted before giving up the ghost.

Attached are what I found. Images are large, I didn't have time this morning to resize them.
Attached Thumbnails
IMAG0002.jpg   IMAG0003.jpg  
-BeNt- is offline  
post #12 of 24 Old 12-12-2011, 08:53 AM
mrblaine
Wizard of Brakes
 
mrblaine's Avatar
1999 TJ Wrangler 
 
Join Date: Dec 2004
Location: Quail Valley
Posts: 33,106
The reason it didn't overheat is due to BELIEVE IT OR NOT, the robust nature of the cooling system and the fact that you aren't in a hot environment right now.

I drove our 04 in 110 heat here in SoCal in the middle of summer for 10-15 miles before it overheated to the point that it blew up the radiator. I was trying to do too many things at once and forgot to raise the fan shroud which pinned the fan blade.

The only airflow the radiator was getting was when the rig was moving. So yours not overheating doesn't surprise me at all.

I am Savvy
blackmagicbrakes.com
Knowledge does not equal understanding.
mrblaine is offline  
post #13 of 24 Old 12-12-2011, 09:28 AM Thread Starter
-BeNt-
Registered User
1998 TJ Wrangler 
 
Join Date: Jan 2008
Location: Scottsboro
Posts: 280
I've been having a heating issue, first noticed in August, while we were in 110 degree temps!! I did a flush a fill on the system back during the summer month and decided to go full heat/defrost to see if I could get it to burp more and I had no heat what so ever then. Kind of forgot about the issue and I thought I had a clogged up heater core and did a flush on it alone back then and did have quite a bit of stuff come out. Come winter time I realized it still wasn't fixed. And as above started troubleshooting.

Even in cool temps, 50 degrees around here as of right now ~30 in the mornings, it would still over heat without something circulating water. I had the same issue back ~8 years ago with a Ford Ranger I had at the time. In the middle of winter it over heated. And to top it all off I've been doing a lot of trail riding in the last few months. I'm totally surprised I never had an issue. All this started back at the beginning of August when my radiator basically blew the top of it off, large crack all the way across the top of it.

Weird indeed, if I wasn't sold on Jeep reliability and build quality by now, I definitely am now!
-BeNt- is offline  
post #14 of 24 Old 12-12-2011, 09:48 AM
mrblaine
Wizard of Brakes
 
mrblaine's Avatar
1999 TJ Wrangler 
 
Join Date: Dec 2004
Location: Quail Valley
Posts: 33,106
Quote:
Originally Posted by -BeNt- View Post
I've been having a heating issue, first noticed in August, while we were in 110 degree temps!! I did a flush a fill on the system back during the summer month and decided to go full heat/defrost to see if I could get it to burp more and I had no heat what so ever then. Kind of forgot about the issue and I thought I had a clogged up heater core and did a flush on it alone back then and did have quite a bit of stuff come out. Come winter time I realized it still wasn't fixed. And as above started troubleshooting.

Even in cool temps, 50 degrees around here as of right now ~30 in the mornings, it would still over heat without something circulating water. I had the same issue back ~8 years ago with a Ford Ranger I had at the time. In the middle of winter it over heated. And to top it all off I've been doing a lot of trail riding in the last few months. I'm totally surprised I never had an issue. All this started back at the beginning of August when my radiator basically blew the top of it off, large crack all the way across the top of it.

Weird indeed, if I wasn't sold on Jeep reliability and build quality by now, I definitely am now!
You should go back to your first post in this thread and compare it to the one you just wrote. I believe very strongly that will help you greatly in the future if you try and get some help diagnosing an issue via the written word.

I am Savvy
blackmagicbrakes.com
Knowledge does not equal understanding.
mrblaine is offline  
post #15 of 24 Old 12-12-2011, 10:00 AM Thread Starter
-BeNt-
Registered User
1998 TJ Wrangler 
 
Join Date: Jan 2008
Location: Scottsboro
Posts: 280
Huh? I did just what I said in the first post? I tore it down one part at a time till I fixed it? Not following you here.

The only symptom was the return line on the H/C wasn't hot originally which lead me to believe it was a blocked/clogged heater core. The top line, coming from the thermostat was hot originally. Over the past few weeks it got to the point neither was hot.

I did a flush of the cooling system and the heater core once again, not as dirty but some stuff did come out. Still no heat. Swapped the thermostat, still no heat. Swapped the water pump, I got heat. I got suggested a vacuum problem and a blend door problem. Someone also suggested I swap out the thermostat.

When I said "Even in cool temps, 50 degrees around here as of right now ~30 in the mornings, it would still over heat without something circulating water." was meaning with my thinking it would still over heat if the water pump wasn't working, but it wasn't. Then gave the reasoning because I had a Ranger which got a bad water pump and it over heated in the winter time, despite 30 degree temps.... Maybe that's the confusion you are having??

You show up after I gave an update to say what fixed it saying your's overheated due to a clutch fan being stuck in place? I have no clue the correlation you are putting on what you are saying, and what I did to fix the issue or ask for help?
-BeNt- is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com 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 e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Any Issues Heating Up A Pitman??? glenn-91YJ YJ Wrangler Technical Forum 12 11-24-2010 04:38 PM
Heating issues: bad blower? gdp057 TJ Wrangler Technical Forum 1 02-18-2010 08:18 PM
Heating issues mario figueroa YJ Wrangler Technical Forum 5 09-13-2009 09:46 PM
Could a clogged cat cause over heating issues? JAC1502 TJ Wrangler Technical Forum 20 07-23-2007 09:40 AM
Weird Heating problem i have no idea YJ Wrangler Technical Forum 10 01-28-2007 09:09 AM

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 On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome