Soft Top + Exhaust question.

Perhaps I dont get it. But...it seems like that if you have no windows, then why worry about CO2 buildup? There is not windows, it cant build up.

It may be referring to the situation where you have the back window open (or removed) without other windows open, there is the risk of carbon monoxide being pulled into the back of the vehicle due to the pressure differences. This is sometimes referred to as the "station wagon effect". I think it's more prevalent in boats, but can happen in vehicles.

Many times I know that I will roll up the rear window on my soft top, and still leave the side windows and the soft doors in (or if you have full doors and don't have the option), and have to be sure to open the passenger window enough to allow airflow through the Jeep from front to back to help avoid this.

Tirya

I've heard the same about not driving without a front window open at least when the back window is zipped up... I've driven around with the back open and windows up, but the air vents were turned on and at full blast so I could have fresh air, just make sure the dial is set for the fresh air and not recirculated air.

It is sneaky and deadly!

I have experience in a TJ getting gassed out to the point of passing out!

A friend has a TJ and we went camping with me riding shotgun. He likes to drive with just the top on and all the 3 back windows out with hard doors.

His GF and he both warned me he is a terrible highway driver because he always falls asleep in the Jeep and he was complaining he couldn't control it. He is also fairly young and inexperienced, so I chalk it up to that.

So we are about a half hour out on the highway and sure enough he is nodding off. We pull over and I take over. He is asleep within minutes and I start to feel bad. Pressure in my forehead and my eyes start closing 'bad' so I open the window and crank up the heater blower and viola come 'instantly' back awake and figure out what is up.

So I try to wake him to get him to roll down his window too. I can't! I have to pull over and physically open the door to get him air!

The rest of the trip was done with all the windows down! We tried it with just the heater on full blast with the front windows rolled up and that did 'not' work. The forehead pressure came back for me pretty fast and he was nodding out again fast.

So basically if you have any of the back windows open or even all 3 out like we did, the front windows must be open too.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Joe Carroll wrote:

Thanks to all, That's exactly the info I was looking for. I rembered a possible problem and just didn't know the specifics. I'll make sure those front windows are always down.

Wow. Scary Mike! Never thought about it like that since I dont usually run that door/top combo. Thanks.

I run with just the Bikini top on and doors and notice fumes if the wind is wrong and the windows up 'usually' only when going slow, but neither my hard or soft doors seal to the top so I can usually run with the windows up and fan on.

At least I know the symptoms of CO poisoning from driving too many rusty old beaters over the years. When my eyelids get abnormally heavy with a heavy forehead, it is time for air Fast!

Mike

jbjeep wrote:

I'm gonna have to think about that for a bit. Although if that was part of the issue with my rig, it ought to be fixed now - I just had a new exhaust put on, the other was leaking...

Mine is all new.

One way to check is to take a battery powered CO detector and hang it from the rear view mirror or shifter....

It is just the nature of square backed vehicles. If you have an opening there, a vacuum vortex forms.

I believe that is also the main reason they won't rent U-haul style trailers to soft tops. It allows a vortex to stay in-between them and fumes can come through the back zippers.

Mike

jbjeep wrote: