Thanks, speedy for the recommendations.

I've never had any heating related problems with any of my F-bodies (LT1 and LS1). They've always been warm and reliable in that category so far. Until this current one...

Heater core is brand new, so I'd assume it is not clogged from anywhere.

So far the most probable cause for the no-neat-situation is then a blockage in the hoses leading to the core. That's what I'm going to have to check next, I guess...

Draining, flushing and refilling the whole system might not be a bad idea, either.

 

Well the ones that didn't have a problem had how many miles on them? Once you get over 100k the problem can start and keeps coming back.

As far as a new core is concerned, since the problem comes from the block, why would it make a difference if it's new? The crud coming from the block loves to get stuck there. I'll bet it's clogged like a fat hampster in a haba-trail. Just had to do mine AGAIN tonight. What a bunch of black filth that came puking outa there. Oh yeah don't use the orange stuff. Makes the problem even worse.

 

Okay. Boy, do we have some heat now!!!

Yes, the lines were clogged. But not the way any of you would ever have guessed.

Check out this junk I got out of the inlet and outlet hoses.

LOL!!! I have no idea what the hell went through the person's mind who did that, but oh well... Probably the heater core was leaking and somebody didn't want to go through the trouble of changing it and decided to prevent the coolant running through the core. Or something...

What ever the intentions were, I got heat now and that's all that matters.

Thanks for all the help and suggestions, guys.

TS