Crazy hot inside my cab

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jsc83

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Harrisburg, PA
I have an 02 TJ with the 4.0L 5 speed. After I drive for about 30 minutes or so, there is a crazy amount of heat that comes from the firewall beneath the dash and the trans tunnel. It's not coming from the vent system, seems to be radiating from the floor boards and trans tunnel. Shifter gets pretty hot as well, which has me thinking a transmission issue. Does anyone else have this issue? The jeep is fairly new to me, so I thought it might have been low on trans fluid. I just replaced that and it was full. Looked like ATF that came out of there, so I'm not sure what was in it. The jeep drives fine otherwise. No issues. No noise from the trans.
Any ideas?
Thanks for the help.
 
Heat radiating from the catalytic converter will make the tunnel and footwell area especially toasty. More so if the carpet has been removed.
 
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Some of these have a tendency to catch fire-it's a good idea to have several large (and I mean the full-size) fire extinguishers on board. Those small "extinguishers" are really no more than a spritzer to cool off your face as you watch your carbeque roil in flame.

The fuel lines run along the driver's side, with a return line that runs somewhat close to the exhaust manifold. As for your transmission, I have never heard of an issue like this from an AX-15. Hopefully someone with more knowledge can offer some helpful advice.
 
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Thanks for the replies. I thought about the cats, but there seems to be a pretty good air gap between them and the firewall. I guess they do get pretty hot. I have some dynamat that I'll try on the floor and see how that works.
 
jsc83 said:
I have an 02 TJ with the 4.0L 5 speed. After I drive for about 30 minutes or so, there is a crazy amount of heat that comes from the firewall beneath the dash and the trans tunnel. It's not coming from the vent system, seems to be radiating from the floor boards and trans tunnel. Shifter gets pretty hot as well, which has me thinking a transmission issue. Does anyone else have this issue? The jeep is fairly new to me, so I thought it might have been low on trans fluid. I just replaced that and it was full. Looked like ATF that came out of there, so I'm not sure what was in it. The jeep drives fine otherwise. No issues. No noise from the trans.
Any ideas?
Thanks for the help.
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There's a reason they put a sticker on the tunnel warning you of the heat!

Make sure your rubber shifter boot is intact. Remove the pleather shifter cover and look down. The rubber boot makes a seal between the tub and the shifter rod. If it's torn or missing, that would explain the extra heat. I have an 04, and I believe that the boot for 02-04 is NLA, but I can't remember?

You can also place some extra heat insulation between you and the cat/exhaust. Some place it between the carpet and tunnel, while others advocate for sticking it to the bottom side of the tunnel (which sounds more logical to me).
 
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RMETeeJay said:
There's a reason they put a sticker on the tunnel warning you of the heat!

Make sure your rubber shifter boot is intact. Remove the pleather shifter cover and look down. The rubber boot makes a seal between the tub and the shifter rod. If it's torn or missing, that would explain the extra heat. I have an 04, and I believe that the boot for 02-04 is NLA, but I can't remember?

You can also place some extra heat insulation between you and the cat/exhaust. Some place it between the carpet and tunnel, while others advocate for sticking it to the bottom side of the tunnel (which sounds more logical to me).
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The inner boot stops a lot of heat. I thought there was a heat blanket under there as well. But the IPC doesn't show it real clear and I'm an not crawling under mine today to check. Im sure someone else will pop in and and confirm or not.

https://wranglertjforum.com/attachments/2002-tj-parts-list-pdf.14038/
 
Mine isn’t nearly as bad as I expected. It was 95 the other day and I actually felt decent in it all day long (my daughter loves it and just wanted to drive around for Father’s Day in the heat).

I was wondering how it would do in actual heat because I took the front carpet out over the winter when it got wet. I left it out to test how hot/loud it would be in the summer because I want to Monstaline the interior. That is definitely happening after last weekend.
 
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jsc83 said:
I have an 02 TJ with the 4.0L 5 speed. After I drive for about 30 minutes or so, there is a crazy amount of heat that comes from the firewall beneath the dash and the trans tunnel. It's not coming from the vent system, seems to be radiating from the floor boards and trans tunnel. Shifter gets pretty hot as well, which has me thinking a transmission issue. Does anyone else have this issue? The jeep is fairly new to me, so I thought it might have been low on trans fluid. I just replaced that and it was full. Looked like ATF that came out of there, so I'm not sure what was in it. The jeep drives fine otherwise. No issues. No noise from the trans.
Any ideas?
Thanks for the help.
Click to expand...
The FIRST thing you need to do is to check the shifter boot from the tunnel to the base of the shifter. Mine was torn when I bought the jeep and replacing it with a new one absolutely KILLED 80%-90% of the in cabin heat issues I had. Think of the hot air and where it comes from, not have that air get sucked into your cabin.

I also added fiberglass backed reflective mating to the underside of the transmission tunnel and above the catalytic converter area. Night and day difference. I don't use AC in the summer and sometimes it gets cooler inside with the windows up that the outside temp is.

edit: I also used silicone to seal all of the mating surfaces from the boot, to the panel and any tiny holes where the carpet clips to the tunnel.

Just my .02
 
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5632 said:
How could that be?
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Simple, if its 90+ outside, the road temps can be in the 120-130 temp range. The hot air is not coming into my cabin any longer. I didn't say it gets in the 60s inside my cabin, I said cooler. Air flowing through the cowl vent(which I also insulated) feels cooler than the hot "not moving air"
 
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