2. While draining I started the engine with heat on full blast till the radiator fan kicked in.
What am I doing wrong? Is there something I am missing?
So when you say it didn't go as expected, you mean you didn't succeed in wrecking your engine, as would be expected by draining it when running?
Can't win them all. Sometimes they are harder to kill than you'd think.
For example, my Lada suffered total coolant loss due to a water pump failure (my fault) but apparently survived my gf limping it off the motorway and parking it up, completely undamaged.
Assuming you dodged that bullet, you then "took it for a spin" knowing
it was more than half empty, and apparently you dodged that bullet too.
Have you considered taking up Russian Roulette on a professional basis, Deer Hunter
You've apparently got air in it. You'll have to try and "burp" it out by squeezing the lower hose suddenly (or do a vacuum fill, as suggested, but I dunno about them). You might try the funnel in the radiator cap trick, but don't run it for very long more than half empty and don't go for any blasts down the freeway, unless you're still feeling lucky.
I THINK I had stubborn air bubbles in my car, some of which I got out with the funnel trick, but some remained, making me think I had a bad head gasket.
Or I had a bad head gasket, but it seems to have got better so it was probably bubbles.
EDIT : You get big syringe-style things here that are designed for unblocking drains. I might try one of those as a "burper" next time, though there is probably something better built for the job available in the US.