I think I just figured something out. In a previous thread I've described how I'm getting no heat from my heater. When this truck was in the shop, they told me the coolant looked like it had never been changed since 1994. It looked like crap. I thought so too. (Just bought the truck used 2 months ago.) It was leaking and I couldn't even identify what was leaking. It was nasty coolant that ran like near sludge or oil.
My thought is, I know nothing about heater cores. Does the coolant run through the core? If so, isn't it possible that crap clogged up the core? Just a thought. I've heard someone mentioned clogged cores before. I've bought a new one an will be installing it this evening if I can along with a new t-stat. Just wanted some thoughts.
MW