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fivestar9968 02-06-2012 02:19 PM

white smoke from defrost vents!!!!!!!! ????
the jeep has been sitting for about a week and a half. i decided to take it out and run it for a few days. so about 10 minutes in a thin white smoke started coming out of both defrost vents for about 15-20 seconds and then went away. i shut the heat off and fan down for a minute. sat there thinking the jeep might be on fire and nothing. started the heat/defrost back up and it actually seemed to be blowing a little stronger than it ever did before and the jeep wasnt on fire. im planning on driving this thing for a couple days should i be worried about something bigger?

Garyk 02-06-2012 02:45 PM

Did you smell any antifreeze, white steam from the heater vents usually indicates a leak in the heater core.

brent in az 02-06-2012 02:46 PM

Coolant-related. Not saying you have a leak in your block, but I'm sure there's a small external leak in the cooling system I'd bet.

Or a fried thermostat on manifold.

Third possibility. On my AMC jeep I had power steering. The return hose sprung a leak to the steering box. Which squirted on upper engine causing white smoke under hood and through vents.

All 3 scenarios happened to me through the years and produced the effect you described.

Nubby55 02-06-2012 07:32 PM

water from rain Could have leaked in the vent, and when it got hot it blew steam in the cab!

dmcg 02-06-2012 07:47 PM

It's your heater core. Just went through this. It will take about 3 hrs and $57 to replace. Be sure to buy one that is direct fit and not "free floating." It's actually a fairly simple procedure to replace. Do a heater core bypass until the core arrives. You don't want to be breathing that crap in

2xs 02-06-2012 08:45 PM


Check your heater core.

fivestar9968 02-07-2012 02:31 PM

i did recently replace the vent cover on my hood to a raised scoop type! and it seems like anything could fall in there and burn up. shouldnt these come with some sort of filter protecting from things falling into the vent from outside? also, it smelled like something burning and it hasnt happened since. i have all fan speeds, i have heat and it blows strong. as far as the power steering thing, i havent seen any puddles underneath and no puddles on the inside from the heater core. so kind of a mystery right now. i had my thermostat replaced about 3 weeks ago and went from a 180 to a 195. the thing was sticking, not heating up plus the housing was leaking. so that should be good also!

Drpinkydo 02-08-2012 05:01 PM

I have a piece of window screen under the cowl vent cover to keep crap out. Works great.

ballistx 02-09-2012 07:48 AM

something burned
It is likely that something was injested into the system from the outside, leaf or something. It dropped across the fan selection resistor which runs quite hot. That is the reason it is in the air stream. That restricted the air flow across the resistor, let it get hot. It stared whatever it was smoking. When it was burned/etc. up then the smoke went away.

Woudn't worry about it unless it starts again. But I certainly WOULD get something over that entry. I had 1 rib broken out of my 98 Ram and that let a mouse get in. He couldn't get out and got decappitated by the squirrel in there. You want to smell something REALLY bad. Fortunately, I was able to rig up a smaller vaccuum hose and sucked him out..

NOT fun.

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