when the cars up to temp and idling for a little slight steam /smoke is coming from the top vents / winsheild defoggers , and smellds like coolant smell .

could it be a bad heater core ? why the steam / smoke ?

 

yes, your heater core is leaking
is there a oily film on your windshield?

 

And look for coolant on the pass. side floor, wet rug.

 

yes theres a film on the winshield and i havnt notice a leakage really , dint drive it that much ,

how hard is it to replace the heater core , or can you remove it but youll have no heat right / kind of need heat for the winter

 

replaceing it and removing it require the same work.. so just replace it... not sure what gen f-body you have.. but the third gen ones can be a 3 hours job if you are not careful.. (hardest part is getting the heater core out.. cause of how the heater box on the inside is put in.. you practically have to remove the nuts holding the dash in and pull it forward so you can get to the all.. and doing it that way is faster than any other way.... (takes about 15 minutes) vs playing with a ratchet to undo the top 2 screws.

 

its a 1994 camaro z28 how hard id it to replace the 4th gen ones ?

 

that i do not know... never had a 4th gen... I would hope it is easier than a third gen....

 

yes my quess would be heater core

 

It's much easier than a 3rd gen.

It should be right behind the glove box. Just take the glove box out, then you should be able to reach the box the heater core is inside of.

The hardest part when I replaced mine, was getting the heater core box sealed back up correctly (small tabs that interconnect)

Thomas.

 

man i wish it were that east on the third. but then we do not have golve boxes ( ould have been something nice to have)