Hello everyone. New to the site and it's nice to see so many helping each other out with problems. My son has a 1995 Sedan DeVille with a 4.9 we changer the thermostat and flushed and changed the coolant the radiator is new but we are only getting cold air thru the defroster and vents. Any help with this would be greatly appreciated.

Have you tried flushing the heater core?

I'm not positive on the 95 Deville but with most GM cars you can watch the heater door open and close through the glove box opening. That would be the first place I would look; to see if it is working. Or maybe I would feel the heater hoses first to see if they are getting hot.

My guess is that you have air in the system. Start the car cold and remove the cap. Run the RPM's up to 3-4K a few times. Watch for air bubbles at the filler opening. Once it warms up and the level starts to rise, cap it up.

You didn't mess with the "T" fitting on the heater hoses did you?

i had a similar problem with my 90, after replacing the heater core, i found out the problem was the t-valve fitting was frozen shut.

I would suspect the t-valve as well, but air lock needs to be eliminated as cause first. After following Ranger's advise be sure levels are good take it for a cruise with heat on full and wait for results. If t-valve is in backwards it might be the problem. Search around the forum for info, but this can effect hot coolant getting to the heater core. After the run feel the two heater hoses going through the fire wall, both should be hot. If only one is, core could be plugged - if both are cold t-valve could be in reverse position. Pull it and reconnect the other way. K_C

Thank you everyone for your replys I will take a look at everything again. To answer Ranger no I did not touch the "T" valve.

Then you can eliminate that. Get the air out of the system.

Bled the air out of the system and the heat is working fine. Thank you for your help everyone really appreciate it.

Just for the record, vice cops are a big waste of tax dollars. Enjoy the gravy train while it lasts.

Just for the record, vice cops are a big waste of tax dollars. Enjoy the gravy train while it lasts.

Just for the record..people need to think before they speak. Maybe in Maine where moose are regurally on the evening news there is not much of a call for a Vice unit in a local Police dept. but in the city of Philadelpha with over 1,700 vice arrest yearly it sure as hell is no "gravy train".