Just noticed the last 2 times I'v driven my jeep that it smokes out of the vents when I turn it off .thought it was steam but not warm so not heater core .What do you think ?

 

Is it SMOKE ...... or WATER VAPOR ?

If the A/C is on, the vents will sometimes spew out wisps of water vapor that quickly disappear. Smoke, on the other hand, will linger for a while before dissipating.

 

Certain temperatures can cause that vapor you see, kinda like opening a deep freezer and seeing the cold vapor. When you shut the engine off, the evaporator gets hit with hotter fresh air and might cause a little vapor.

If heater core was still suspect, its vapor usually has a distinct bitter/sweet smell, and it usually causes a fog/film on the windshield above the defroster grills. Along with a gradual loss of coolant and possible pass floor getting wet.

 

So i'm realy leaning tords the core ,I'v had them go out before and i know that SMELL,This time i could of smelled it for the slightest sec.but no steam or fog on winsheld ,,,TOO SOON maybe ??

 

Might be too soon to tell, you might try using the DEF position a little more, and maybe select the temp setting to hot too. This allows most or all the HVAC air to go through the heater core and direct it to the windshield.

Keep a close eye on the coolant level and reservoir, it the core is leaking the coolant level will go down, if its a small leak it might take a few days to notice. Also the carpet may become wet from underneath, so you might tug on it enough to get a hand down there at the pass floor area. Coolant will feel oily or slick on the fingers, and if you arent scared it will taste sweet/metallic like

 

Nice ,I'll keep an eye on all except the TASTE of metallic..It's just a weekend beater ,but id hate for it to blow out and burn my foot for a 2nd time