1996 Plymouth Voyager 6 cyl Two Wheel Drive Automatic 101000 miles
my heater is blowing cold air even when engine tempeture is normal. I think I saw a white vaper cloud coming from the underside of car a week ago while driving on freeway and this was about the same time I lost heat. Blowers seem to work fine, but no heat. I put in about half a bottle of anti- freeze but this didn't help.
Try warming the Vehicle, then carefully feel the heater hoses, are they both hot? If one is cooler than the other, You need to flush the core, or do a replacement job on the heater core. Also if the system has a heat control valve on the heater hose, make sure it is working! Also check the thermostat, and the temperature blend door, thats under the dash, in the heater plenum. You can flush this yourself, buy the prestone flush kit and install the tee in the heater return line. Disconnect the heater hose at the waterpump, clamp the hose in back of the tee you installed and back flush till it runs clear.20 mins or so.