Heat Problem... Need advice

I have a 1998 Intrigue and even after the engine warms up, i get heat only sometimes. Other times, i will get heat, but then it will fade to cold air! (it's winter here in New York... brrr.) Sometimes I can shut off the heater and it will blow hot again... but most times will still blow cold. I have the "wonderful" digital climate control option. Anybody have any ideas? Thanks in advance!!

Gearhead1175

http://www.automotiveforums.com/vbulletin/showthread.php?t=668081

search the Intrigue forum for "no heat" and read some of the posts.

I looked at every thread that has been posted about heat and A/C... doesn't seem to be the same situation. The air coming out of the vents comes out of he proper vent(s) I choose. The problem i'm having is that the temp changes on it's own and the cabin never warms up. (Nothing like having cold outside air blowing on you in sub zero temps!!) Any ideas? Is the a vacuum controlled door that allows a certain amount of hot air thru into the ducts?? Thanks

I can relate because I am also from NY. Just had the same problem with my 98 Intrigue. I Back flushed the system, manually flushed the heater core and replaced the Thermostat. All is well now.
I think it had something to do with the Dex cool anti freeze sludging up.