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-   -   Heater problems (http://www.wranglerforum.com/f210/heater-problems-112464.html)

scgeek12 09-12-2011 01:33 PM

Heater problems
 
Ok last winter SUUUCKED without a heater in the jeep and i would really like to get it fixed before it snows again, i WAS thinking about putting a space heater in the jeep on a 2000W inverter but jerry kindly showed me some simple math and proved this wouldnt work because it would be drawing over 130 amps off my battery :-/ so i think my best bet is to fix the jeeps heater, ive been working on it on and off for about a year now

problem- even after the engine is at 210 degrees and has been for a while the heater only blows lukewarm at best air, not even enough to notice unless you put your hand over the vent, also it blows out of the floor vents at all times except when it is on defrost, then it only blows from the defrost vents, it doesnt seem to get any warmer weather im idling or driving, atleast not enough to notice (cold is cold!) the fan would only work on the second to lowest setting but i replaced the climate control panel (all 3 switches) and it blows on every setting now,

diagnostics so far- i can feel / see the blend door actuator moving freely and fully, today i went out and listened and i can clearly hear a "thud" when the blend door closes (on full heat) so it is moving, and i dont here any air going around it, both of my heater core hoses are hot to the touch, but there is a weird fitting about 6" after my water pump that says "PRESTON ANTI-FREEZE COOLANT KEEP TIGHT" on it and if you unscrew it , it looks like maybe a garden hose could screw onto it to help flush the system? do all jeeps have this??? (see pic, ill take better one when my camera is done charging)

what i think is wrong- well looking around and playing with it today i took a peek down the cowl inlet (just aft of the hood) and i can feel it sucking in a good deal of air BUT it looks like the vent that goes up into it has been cut? i can see it if i look through the hood and it is pretty jagged on the edges and there is a little bit of what used to be a seal hanging down off it, i have NO idea why someone would cut this? and it is now open to the air under my hood, BUT im not sure this could be the problem because doesnt that air get passed over the heater core after that anyway? so it wouldnt matter what temp it was when it got sucked in? (maybe they cut it to let warmer air in from the engine bay?) again ill take pics of what i mean in a few minutes and post them but any ideas on what i could check next would be great (its about 85 outside right now so of course the dang heater is blowing hot as heck lol so kind of hard to diagnose) :banghead::banghead::banghead::banghead:

arcountryboy 09-12-2011 01:42 PM

Have you tried to flush the heater core out?

Mine was doing practically the same thing and worked right when I flushed the heater core. Of course, the core went out about 2 weeks later.

Moose-Island 09-12-2011 01:46 PM

but there is a weird fitting about 6" after my water pump that says "PRESTON ANTI-FREEZE COOLANT KEEP TIGHT" on it and if you unscrew it , it looks like maybe a garden hose could screw onto it to help flush the system?

That sounds like a Prestone cooling system flushing fitting. I had one on my MG years ago. It is my impression that it was an aftermarket item.

scgeek12 09-12-2011 01:47 PM

Quote:

Originally Posted by Moose-Island (Post 1563185)
but there is a weird fitting about 6" after my water pump that says "PRESTON ANTI-FREEZE COOLANT KEEP TIGHT" on it and if you unscrew it , it looks like maybe a garden hose could screw onto it to help flush the system?

That sounds like a Prestone cooling system flushing fitting. I had one on my MG years ago. It is my impression that it was an aftermarket item.

ive seen the kit and thats what made me think that, im uploading pics now

scgeek12 09-12-2011 01:48 PM

Quote:

Originally Posted by arcountryboy (Post 1563175)
Have you tried to flush the heater core out?

Mine was doing practically the same thing and worked right when I flushed the heater core. Of course, the core went out about 2 weeks later.

havent flushed it yet because both lines are HOT to the touch, but i might just do it later, altho i REALLLLY dont want to replace the core lol!!!

scgeek12 09-12-2011 01:52 PM

ok heres the pics-

this is the line comming off the water pump going to the core and the fitting i mentioned-

http://a5.sphotos.ak.fbcdn.net/hphot...45097685_n.jpg

and here is the cap on the fitting
http://a5.sphotos.ak.fbcdn.net/hphot...26524011_n.jpg

here is a view of the duct comming from the cowl that looks like it has been cut (pic taken from the engine bay directly aft of the valve cover)

http://a7.sphotos.ak.fbcdn.net/hphot...52055573_n.jpg

pic of the cut duct again from above the valve cover

http://a8.sphotos.ak.fbcdn.net/hphot...78595011_n.jpg


and heres a pic looking down into the cowl from above it it looks like the duct should be covered somehow?
http://a1.sphotos.ak.fbcdn.net/hphot...92016269_n.jpg

pic of the same thing but closer for a better view
http://a2.sphotos.ak.fbcdn.net/hphot...65857117_n.jpg

scgeek12 09-12-2011 01:54 PM

it would seem since there is an aftermarket flushing fitting on there,and obvious attempts to cut the duct to let hotter air into it that the PO was having problems with the heater as well, but i dont know what else to check :(

scgeek12 09-12-2011 01:59 PM

Quote:

Originally Posted by Moose-Island (Post 1563185)
but there is a weird fitting about 6" after my water pump that says "PRESTON ANTI-FREEZE COOLANT KEEP TIGHT" on it and if you unscrew it , it looks like maybe a garden hose could screw onto it to help flush the system?

That sounds like a Prestone cooling system flushing fitting. I had one on my MG years ago. It is my impression that it was an aftermarket item.

think your right here is a preston flushing kit and it looks just like one of those fittings-

http://ecx.images-amazon.com/images/I/51G%2BBb4rVbL.jpg

scgeek12 09-12-2011 04:07 PM

just tried my A/C for the first time lol, and it doesnt blow very cold either, it blows decent at the floor but the middle vents is only a little cold, so im thinking maybe the blend door is closing (because i here the "thud") but not sealing?

arcountryboy 09-12-2011 09:00 PM

I have the same valve on mine, it is the flushing kit. If your air and heat are both not working, I'm going to say the blend door is not fully functional. Also, the duct is not cut, but the foam gasket is partially missing. Mine looked the same way. I used 3M foam weather stripping/camper shell tape to make a gasket for it.

Shelby427 09-12-2011 09:05 PM

Yes that is an add on Prestone flush tee installed by a PO.

Try to flush the core BOTH directions. A blocked heater core can have both hoses hot.


The center duct is your cowl water drain. Looks like the foam deteriorated, and fell off.

1 nut holds it to one of the evaporator case bolts, its on the right side. Pull it off, clean it out, and you can replace the foam with new stuff from Home Depot or Lowes.
Look for it in the weatherstripping section.

As for the 'blocked" fresh air intake, it's factory. That plate is to help stop rain water from running straight into the fresh air intake below it. If it wasn't there your floor on the passenger side would be soaked each time it rained.

You have multiple doors on the evaporator/heater case. Fresh-recycle, heat-a/c, and mode(s).

All vacuum operated. You may hear one door working, but maybe not all of them are.
Bad switch, kinked/leaking vacuum lines, loose or broken linkage from the vacuum motors, or even a broken door.

Takes some doing to see em, but it's worth it to see where your problem is.


And how do I know all this stuff? Well I've been doing it for 35 years which means squat, but I changed the evaporator/dryer/orifice and heater core in ours yesterday.

Wasn't really that bad, OK except for the 3 thousand 7 hundred and 48 screws that have to come out the the dash to pull it. Or so it seemed.

Luckily they are all the same, save for a couple and it's obvious where they go.

Granted I've been doing this stuff for a while, but it still took me nearly 7 hours start to finish, and that includes evacuating and recharging the a/c.

jp2611 09-12-2011 09:06 PM

It can't be this easy--but I will say it any way-----could you be getting a vacuum from the missing seal? SO that in the winter you get the cold air and the summer you get the hot? I mean if it didn't need to be sealed why did they?

s14sh3r 09-12-2011 09:06 PM

Haven't done it on my Jeep, but I flushed the heater core out on my Blazer a couple years ago and it works fine now. Pull both hoses off and use a garden hose and flush until clear, then do the other hose. Repeat until it runs free and clear.

scgeek12 09-12-2011 11:21 PM

im going to try and flush it 2morrow, well later today i guess since its past midnight lol, thanks for the info so far, also shelby ive read quite a few great posts from you and you seem to know what your talking about! ill start chasing the vac. lines i guess :( lol

scgeek12 09-28-2011 02:20 PM

sorry for not updating this been pretty busy, i flushed the system and it helped a little, BUT i found that if i turn the temp knob all the way to full hot, then back about an 1/8 of a turn it actually gets pretty hot, but full hot it gets cooler... its a brand new switch so not sure why, either way its good enough to get me through the winter lol, thanks for all the help on this and replies!

smccollamjr 09-28-2011 09:52 PM

Is there a calibration procedure? I was having trouble with the climate control on my Silverado. I found a procedure on line to calibrate the HVAC system and it fixed it.

Shelby427 09-28-2011 10:31 PM

Hmm,wonder if maybe you might have a weak vacuum source.
Off the top of my head, if the engine isn't producing a high enough vacuum rate, the system may not have enough guts to pull the door fully open/closed. Back off the switch a little and it has just enough to hold it there.

Yep it does have a vacuum reservoir, but it only holds the amount it's fed. Full at 18 psi is stronger then say full at 12 psi of vacuum. That's why it's there. As engine speed increases, vacuum pressure drops. So the tank holds a reserve to compensate.

But if it was being supplied a low enough source to begin with it could easily do this.

Would be like old jeeps with vacuum powered wipers. No reservoir on them. Wipers worked great at idle. But would slow to a crawl running down the highway.

Also you may want to look at the main vacuum line from the intake to the reservoir and the tank itself. Leaks at either could cause a weak feed to the the HVAC unit controls.

scgeek12 09-29-2011 05:33 AM

Quote:

Originally Posted by Shelby427 (Post 1613031)
Hmm,wonder if maybe you might have a weak vacuum source.
Off the top of my head, if the engine isn't producing a high enough vacuum rate, the system may not have enough guts to pull the door fully open/closed. Back off the switch a little and it has just enough to hold it there.

Yep it does have a vacuum reservoir, but it only holds the amount it's fed. Full at 18 psi is stronger then say full at 12 psi of vacuum. That's why it's there. As engine speed increases, vacuum pressure drops. So the tank holds a reserve to compensate.

But if it was being supplied a low enough source to begin with it could easily do this.

Would be like old jeeps with vacuum powered wipers. No reservoir on them. Wipers worked great at idle. But would slow to a crawl running down the highway.

Also you may want to look at the main vacuum line from the intake to the reservoir and the tank itself. Leaks at either could cause a weak feed to the the HVAC unit controls.

hmm that might be it, will try to check on friday, just got off a long shift and got to get up for work again soon lol, but if i turn the heater on to any setting (or A/C) and turn the fan from the lowest setting to the highest quickly nothing will come out it will make a "sucking" sound, but if i go from the first setting, to the second, to the third, to the highest slowly it will work just fine in every setting, not sure where the accumulator for the system is but ill check the FSM at work 2morrow and check out that vac. line, thanks!:thumb:

Shelby427 09-29-2011 12:37 PM

It's mounted under the battery tray. Just follow the hose from the rear of the intake.
It comes off the intake, runs across the top of the firewall/cowl. Tee's off in the center of the firewall/cowl to feed your HVAC, then continues on to the reservoir.

erickpl 09-29-2011 01:24 PM

I had issues with my heater not working well at all. Did a flush/reverse flush and it didn't help... until I noticed the water pump waterfall. Took it off and the impeller wouldn't even turn freely at ALL.

Replaced it for about $35.00, installed it and have been enjoying heat since.

During that time, I NEVER overheated at all. Just a thought.

scgeek12 09-30-2011 04:43 PM

Quote:

Originally Posted by Shelby427 (Post 1614265)
It's mounted under the battery tray. Just follow the hose from the rear of the intake.
It comes off the intake, runs across the top of the firewall/cowl. Tee's off in the center of the firewall/cowl to feed your HVAC, then continues on to the reservoir.

found the line, it looks to be in decent condition, altho right where it goes into the accumulator it is COVERED in mud and MIGHT be dry-rotted a little bit, im about to go see if i have an extra peice that will work, is it supposed to be a hard vac. line that comes off the back of the intake? it comes right off the back into a "T" and splits off, 1 goes to the cruise control servo the other continues along the path you describes (its very loose seems like the line is to long?) then another "T" and goes to the HVAC then down to the accumulator, the line looks newish except that one end where it goes to the accum, if i have an extra peice ill try the heater tonight when its cools down and let you know!

Quote:

Originally Posted by erickpl (Post 1614372)
I had issues with my heater not working well at all. Did a flush/reverse flush and it didn't help... until I noticed the water pump waterfall. Took it off and the impeller wouldn't even turn freely at ALL.

Replaced it for about $35.00, installed it and have been enjoying heat since.

During that time, I NEVER overheated at all. Just a thought.

checked around the pump pretty well and dont see any signs of a leak at all, also i can feel the fluid moving through the lines pretty good and i pressure checked the system while i was out there and it checks out good :thumb:

scgeek12 09-30-2011 04:55 PM

just went and pulled the vac. line off the accumulator and quite a few big clumps of mud came out lol, (note to self- wear safty glasses next time) i cleaned it out with some throttle body cleaner (the line) and am going to see if that works, it doesnt look dry rotted at all now that its clean, going to laugh if i froze all last winter because of mud :-)

digio12 11-20-2011 03:58 PM

5 Attachment(s)
I have been following this thread for awhile now because I am having a similar problem in my 98 TJ (also not getting any heat).

[FYI photos attached below]

Today, I pulled the control panel off and found that there is a little red clip that holds the braided metal cable that (I am assuming) is the control cable for the mixing door. This clip slipped out of place causing the temperature control cable to not fully extend from left (cold) to right (hot). I placed it back into the slot where it appears to belong so when the temp control is swiped from left to right it stays put and you get the full range of movement - I thought I fixed my problem for sure. But I still wasn't getting any heat :confused:. The funny thing is that I get cold air when it is turned to the left...

I, also, have one of those aftermarket Prestone flush tees in the upper heater hose and make it a habit to flush the system about every 12 months with the heat on to flush the core also (I had to replace the entire cooling system including both heater hoses and both radiator hoses as well as the radiator itself when it blew from overheating a few years back - the heat HAS worked after this repair but doesn't now). The upper hose is hot when at operating temp (I think my t-stat is 190 degrees or so) but the lower hose doesn't get hot.

Please keep in mind, I am a novice fix-it-yourselfer and I read a lot of information about vaccum lines, accumulators, etc. in this thread and I am getting a bit lost in it all.

So I guess here are my questions:

1. Does the lower heater hose need to be hot at operating temp to get heat?
2. (Follow up) If it isn't hot, what should this tell me?
3. Does the red clip that holds the mixing door cable in place stay put somehow - it seems to slip out?
4. How would you further troubleshoot this issue?

I would appreciate any feedback and please remember that I am begrudgingly a layperson when it comes to this stuff so if responses could be dumbed down just a notch or two it would be greatly appreciated!

Control panel type
Attachment 78609

Red clip back in place
Attachment 78610

Top of assembly (guessing colored wire cluster is vaccum lines?)
Attachment 78611

Top of assembly, detail
Attachment 78612

Heater hoses with flush tee; top hose hot, bottom hose not
Attachment 78619

digio12 11-20-2011 04:00 PM

BTW, scgeek12 have you had any success??

scgeek12 11-20-2011 05:59 PM

nope, i just bought a 2000W inverter and a small 200W space heater, it gets the job done for now lol i put on some tube fenders recently and moved the vacuum reservoir up to the blank tray on the opposite side of the battery tray and replaced all the vacuum lines with no help, i am going to try and flush it 1 more time to see if that does anything but if not im just going to buy a bigger coat lol

scgeek12 11-20-2011 06:03 PM

btw yes both heater hoses should be hot, according to the FSM the lower hose is the inlet side so if that one is not getting hot i would imagine your water pump isnt pushing coolant to the core, but that doesnt make any sense if your other (top) hose is hot, maybe they are mixed up somehow? i have the FSM for a 99 so its 1 year newew but i wouldnt think they would change that, as far as the slide im not sure on that one mine has the knobs not the slides so its different

scgeek12 11-20-2011 06:05 PM

reading on in the FSM it does say " Engines from previous model years, depending upon application, may have been equipped with a forward (clockwise) rotating water pump. so that might explain the hoses but it still might be something to look into

scgeek12 11-20-2011 06:08 PM

actually i just found a better pic further down the FSM cooling system and it looks like the (on mine) lower hose is the inlet coming from the T-stat, and the upper hose is the outlet going to the waterpump, so might be your T-stat is stuck closed


http://fixautopartz.com/wp-content/u...ng-system1.png

digio12 11-20-2011 07:59 PM

Very interesting. I wonder if the upper hose is the inlet or outlet on the 98... I guess I can't tell if it is stuck open or closed if I don't know which way the fluid is going. Also, the engine doesn't overheat if that makes a difference.

scgeek12 11-21-2011 08:40 AM

Quote:

Originally Posted by digio12 (Post 1759783)
Very interesting. I wonder if the upper hose is the inlet or outlet on the 98... I guess I can't tell if it is stuck open or closed if I don't know which way the fluid is going. Also, the engine doesn't overheat if that makes a difference.

you can take your thermostat out and put it in a pot of water and boil it on the stove, if it opens up when it gets hot its ok, if not then its bad, it might not be overheating because its colder outside, which is why your trying to use the heater :) easy test, or just toss a new one in since they are cheap


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