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Unread 12-13-2003, 09:01 PM   #1
alilredjeep
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1992 YJ Wrangler 
 
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Blocking off the cowl vent for more heat

Does anyone know what kind of trouble I'm asking for if I completely block off the cowl vent on my 92 wrangler.
I duct taped up about 2/3 of the vent this morning while I was letting my YJ warm up and drove it to work that way. It seemed as though the heater worked a little better but not as good as it might have if I had taped off the vent completely.
I know that cold outside air is being pulled into this vent while the heater is running at full blast while the jeep is parked and warming up because I could feel the cold air as it was rushing by my hands.
I dont want to cause any problems from something getting too hot from no cooling but at the same time I want a better working heater.
BTW, I have already replaced the thermostat, the heater core has been flushed and the radiator is practically new so I know that they aren't the culprits for weak heat.
Does anyone have any thoughts on this? Is it a bad idea to seal off the cowl vent?

TIA
alilredjeep

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Unread 12-13-2003, 10:34 PM   #2
Dembones
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That's the heater intake, you wouldn't get any airflow to the heater if you blocked it up so your heater wouldn't work at all. As a bonus you may just fry your fan motor . It'd be the same as putting duct tape over your air box intake, bad idea IMO. I'm sure you've heard it before but maybe what you're getting is all your heater was designed to give. Mine is cold for a while but in a few minutes it could singe a cactus. It probably just felt warmer because you were getting less air in, but the air that made it was warmer than if the vent was open. Hope you get this figured out, good luck!
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Unread 12-14-2003, 08:09 AM   #3
Six Shooter
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You mention changing the t-stat. What does your temp. gauge show. It should be up around 200 give or take a bit. I have relaced t-stats before and found the new one to be bad. Maybe its something as simple as that. Keep us posted.
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Unread 12-14-2003, 07:59 PM   #4
alilredjeep
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Quote:
Originally Posted by Six Shooter
You mention changing the t-stat. What does your temp. gauge show. It should be up around 200 give or take a bit. I have relaced t-stats before and found the new one to be bad. Maybe its something as simple as that. Keep us posted.
The stat is rated at 190 or 195 and the guage reflects this temperature when it is fully warmed up. Also I've noticed no circulation in the radiator when the engine is cold and then as the engine warms up and the thermostat opens, circulation will begin.

Something else I'm curious about and I don't mean to write a long boring novel but here goes....

#1 This particular YJ was sold new in Northwest Florida and I'm wondering if there might be a difference in the way the heating system was designed for Wranglers sold new in the southern most states.

#2 Is there a way to make the heater fan recirculate the warmer air from inside the cab back around through the heater core rather than use the colder outside air coming in through the cowl vent? The reason I'm asking is I'm wondering exactly what the little square vent is for on the heater box on the far right and next to the kick panel. It looks to be an intake vent for the heater core box with springs and metal rods going to it.

#3 Is it possible that a weak radiator cap could be bleeding off pressure to the overflow and hindering the effort of the heater to function at its best?

#4 Wouldnt snow cover the cowl vents on Jeeps being driven up North and cause the same problems described as using duct tape to cover my cowl vent?

alilredjeep

And just for laffs:
Hell would freeze over if it had to depend on a heater like the one in my YJ =D
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Unread 12-14-2003, 09:47 PM   #5
Banshee
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alilredjeep

As far as your #2 question goes. I have to push in on the recirculator door to get it to come open and it makes a great differance. I have not got a chance to see why it sticks shut but I know I froze my butt off the other day when it was 17 deg. Untill I opened the little door. This is my first Jeep and I have only had it a week so thats about all I can tell you.




Quote:
Originally Posted by alilredjeep
The stat is rated at 190 or 195 and the guage reflects this temperature when it is fully warmed up. Also I've noticed no circulation in the radiator when the engine is cold and then as the engine warms up and the thermostat opens, circulation will begin.

Something else I'm curious about and I don't mean to write a long boring novel but here goes....

#1 This particular YJ was sold new in Northwest Florida and I'm wondering if there might be a difference in the way the heating system was designed for Wranglers sold new in the southern most states.

#2 Is there a way to make the heater fan recirculate the warmer air from inside the cab back around through the heater core rather than use the colder outside air coming in through the cowl vent? The reason I'm asking is I'm wondering exactly what the little square vent is for on the heater box on the far right and next to the kick panel. It looks to be an intake vent for the heater core box with springs and metal rods going to it.

#3 Is it possible that a weak radiator cap could be bleeding off pressure to the overflow and hindering the effort of the heater to function at its best?

#4 Wouldnt snow cover the cowl vents on Jeeps being driven up North and cause the same problems described as using duct tape to cover my cowl vent?

alilredjeep

And just for laffs:
Hell would freeze over if it had to depend on a heater like the one in my YJ =D
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Unread 12-15-2003, 07:44 AM   #6
scorpionkill
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My Jeep is doing the same thing. I have the heater on full blast and it is blowing really hot but cold air is rushing in somewhere up under the drivers side dash (seems to be coming from the heating unit somewhere) the heat is heating the cab but it is fighting the cold air that comes in just as fast. I thingk something is stuck open up there. It sucks because my right leg freezes while driving.
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Unread 12-15-2003, 09:42 AM   #7
Jay Blanton
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Not to be a know it all, but I have already found the answer to the problem last year. The little vent box in your jeep is an intake and recirc. box. I shut my cowl vent off during the winter with a painted peice of plexi glass. I take it off during the summer for A/C use. I put that on this summer.... It is a jeep, so get use to it being cold.. You get what you pay for. The thermostat on my old 4 bannger, always stayed at 210-212. alittle to hot... I put 160 degree on there, and I lost heat, but gain power. (sorry, I'm a power buff.) It wasn't to unbareable as long as the vent on top was closed, and the jeep had plenty of time to warm up.

For my birthday last year my family got me heated seats ( They are probaly the best feature on my Jeep.) Then I went out and bout a remote starter, and then i could sit in my room and warm up the jeep. Says from making raisins in the morning...

hope that helps

Jay
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Unread 12-15-2003, 05:34 PM   #8
Limpin
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guys dont forget theres a water runn off for that cowl..

if you completely block it off to the actual cowl *outside* your going to be pulling air from the enginebay.. but you wont be able to pull as much air..

oh and i took out my heater and ac, so now i have a gaping hole where the heater was in my firewall.. 27 degrees this morning.

and there is heat coming in from the enginebay too so i have heat on the passengers feet just not mine where its needed
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Unread 12-15-2003, 07:08 PM   #9
alilredjeep
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Quote:
Originally Posted by Limpin
guys dont forget theres a water runn off for that cowl..

if you completely block it off to the actual cowl *outside* your going to be pulling air from the enginebay.. but you wont be able to pull as much air.
Limpin,

If you mean pulling air through the drain hose that is attached to the firewall side of the cowl....... isn't that hose pinched off on the end so that engine bay fumes can't be drawn into the interior when the vent is turned on.
I hope I made myself clear enough for you to understand what I'm trying to say.

Also, I see your from P'cola.......Thats where I bought my YJ from this past march March and about 90 minutes south from here.
We're practically neighbors!!

alilredjeep
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RED JEEP CLUB MEMBER #92

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Unread 12-16-2003, 10:42 AM   #10
cookie
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Quote:
Originally Posted by alilredjeep
Limpin,

If you mean pulling air through the drain hose that is attached to the firewall side of the cowl....... isn't that hose pinched off on the end so that engine bay fumes can't be drawn into the interior when the vent is turned on.
I hope I made myself clear enough for you to understand what I'm trying to say.

Also, I see your from P'cola.......Thats where I bought my YJ from this past march March and about 90 minutes south from here.
We're practically neighbors!!

alilredjeep
ok pardon my ignorance but here it goes; you live in florida and u need heat? lol hello from up north, and with heat to spare i'll send u some of ours...lol.. minnesota
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Unread 12-16-2003, 11:00 AM   #11
AZ95YJ
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Be happy that your heater blows. My heater hasn't blown for the past 5 years (practically since I got my Jeep). One day my friend and I wanted to replace my speakers because they weren't doing so well. So, we tried (key word) to pull of the entire dash. Needless to say we couldn't get it off (something was still holding on behind the steering wheel and I didn't have a factory service manual, yet). So we were only able to replace the passenger side speaker, and after that my heater has never blown a single puff of air. I always have to let it vent in.

But, I'm not sure about your problem. I just wanted to say , be glad that yours works.
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Unread 12-16-2003, 11:20 AM   #12
RCHavok797
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Quote:
Originally Posted by AZ95YJ
Be happy that your heater blows. My heater hasn't blown for the past 5 years (practically since I got my Jeep). One day my friend and I wanted to replace my speakers because they weren't doing so well. So, we tried (key word) to pull of the entire dash. Needless to say we couldn't get it off (something was still holding on behind the steering wheel and I didn't have a factory service manual, yet). So we were only able to replace the passenger side speaker, and after that my heater has never blown a single puff of air. I always have to let it vent in.

But, I'm not sure about your problem. I just wanted to say , be glad that yours works.
When you tried to remove your dash did you lower the windshield and remove all the screws there?
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Unread 12-16-2003, 12:17 PM   #13
AZ95YJ
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Yes, and there are a lot of screws there. (annoying)

Maybe I should get a helmet, some cool sunglasses, and drive around with my wind sheild down. That would be so much fun.

Last edited by AZ95YJ; 12-16-2003 at 12:19 PM..
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Unread 12-16-2003, 04:16 PM   #14
alilredjeep
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Quote:
Originally Posted by Banshee
alilredjeep

As far as your #2 question goes. I have to push in on the recirculator door to get it to come open and it makes a great differance. I have not got a chance to see why it sticks shut but I know I froze my butt off the other day when it was 17 deg. Untill I opened the little door. This is my first Jeep and I have only had it a week so thats about all I can tell you.

Banshee,

Thanks for the tip. It was stuck shut on my YJ too.
I thought I was gonna break something trying to push it in but it finally gave way and began to recirculating the warmer air from inside the cab.
From the looks of it, that recirculator door devides the outside air from the interior air.
Anyway, Thanks again and too everyone else who took part in this thread I also Thank you for your ideas

alilredjeep
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RED JEEP CLUB MEMBER #92

'92 WRANGLER, 2.5 Litre, 5 Speed, Rag Top, Superwinch LP8500, Cepek 130W Driving Lights, 31x10.50/AT with no lift, Of course! It rubs!
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Unread 12-16-2003, 04:39 PM   #15
Limpin
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glad you found that
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