No/ Weak Heat

[LemonPie]

Heater only blows outside temp air or luke warm air, never hot. One of the lines to the heater core was cold. I flushed the heater core lines with the prestone inline t hose connector kit. I even bought a t for each side of the heater core and flushed from both sides.. Anyways both hoses are hot now so I assume the heater core is getting hot as now I can sometimes feel luke warm air opposed to outside temp, coolant is topped off as well and I ran without the cap on for awhile to ensure no air bubbles.

 

I've checked the blend door actuator and it's good, a little slow but it's good. I even took it off and spun the door by hand all the way each way to check. I've got no idea whats next. I did a little research on the forum and found someone with a 99 and a similar problem, the guy said he hit another blend door by the passenger side and heard it clunk and the air started working suddenly.. I wasn't as lucky as this fella. Any suggestions would be appreciated.

 

Edit: Incase you didn't see under my name I'm referencing a 2000 chevy silverado with the 5.3.. thanks!

[Nytemare]

you could have a plugged heater core. Just enough flow to make the other hose hot.