99 Grand Prix GT anti freeze smell in cab?

[dusterdude]

OK here goes, We have a 99 Grand Prix GT with around 105k on it, Getting a antifreeze smell inside the car after the engine warms up. Befor you go saying heater core, wouldn't the windows be getting a scum or film on them.( had a old car once with a bad heater core and it would make a mess of the windows and almost put a fog inside the car). No visual signs of antifreeze around the outside of the heater box or on the floor in the carpet, under the hood no signs of leaks anywhere, just started doing this not long after a new thermostat was installed.I know the rad. needs flushed but I didn't have time when i put in the thermostat.
Does the temp control valve stay open when the car is shut off. could do a cooling system pressure check and if it leaks down bypass the heatercore and try it again. Just a thought. I know there are people on here that are a lot smarter than me. any help would be grateful..........

[GTP Dad]

Check the hoses to make sure they aren't leaking especially when the car is cold. Also check the area around the thermostat housing as the housing may be loose and causing a leak when cold. When it gets hot it could seal and then leak again. The smell could be coming from the antifreeze boiling off when the engine gets hot and the smell is being sucked into the car by the hvac system.

[GaryFenza]

The Heater Core could be leaking, we fixed one at our garage and thats exactly what the problem was. on some of the older models i believe the heater core hoses were rubber and were known to eventually crack and leak anti freeze everywhere whould could cause the smell in he cabin