2000 Gmc Jimmy New Heater Core.. No Heat

[acavanaugh4]

I have a 2000 GMC Jimmy. we recently replaced the heater core in it. i had heat for about half a day. we now have no heat. it does not heat up to 210 at most to the line below it but normaly stay 2 lines below 210. there is a swishing/gurgling noise comeing from the heater core that you can hear when you excellerate. read on a site that i needed to "burp" it. so i tried that. i had some heat but was only luke warm and only last max 20-30 min. i never have hot heat. after i shut the truck off and trun it back on im back to square one. checked the hoses they are on right. here in Indiana its been in the low teens and i cant be haveing my son out in the weather in a truck with no heat!!! PLEASE HELP!!!

[Black02Silverado]

Is the truck getting up to temp after you "burped" it? If not sounds like a bad thermostat stuck open. If it is getting up to temp then it sounds like the blend door is sticking closed and not allowing heat into the cab.

[acavanaugh4]

it never gets above 210 regardless. will try changing the thrmostate and see if that helps!! will let you know!! thanks for the info!

Is the truck getting up to temp after you "burped" it? If not sounds like a bad thermostat stuck open. If it is getting up to temp then it sounds like the blend door is sticking closed and not allowing heat into the cab.

[acavanaugh4]

Changed the thermastate. and we still have no heat. but when we turned it to max ac. had here for a few mean. was not exactly hot but was warmer then luck warm. but it did not last long. truck still dont get up to 210..maybe its not suppost to buti still have to heat.. idk what else todo!!! ...its like its stuck on ac or something

[233monte]

It could be that your blend door is stuck or broke or the actuator stopped working. When you had the heater box out and split it, you could have damaged the door.