Air bubble in heater core

Did you get to the bottom of this at all? I have the same issue going on 4 years. Its hard to remember perfectly but I could have bought the truck like this, or it could have happened when I bled the whole system to do my water pump 4 years ago. I could never get it out so i just lived with it. I have tried multiple times bleeding it on the most extreme incline i could find, squeezing hoses, revving the engine with cap off. Thought 15 minutes (after warm) was long enough idle And it seems like everyone glazed over post #10 about a failing head gasket, it seems hyperbolic, but It makes me wonder if we both have this issue possibly? Head gaskets can fail without the obvious milkshake oil/coolant or exhaust smell symptoms. I'd just be surprised that (at least in my case) i've been living with it for 4 years, but sometimes weird things happen.

 

My 05 has 223k on it and has been doing this for the last 15k miles or so. Headgaskets will probably go soon. I dont put but maybe a few thousand on the truck a year now but im preparing myself.

11/04

 

I'm going to bleed the frig out of it today and try to get the air out again. Saw a video of a guy who said he had to "hold it at 3-3500 rpm for a solid 6 or 7 minutes" to get all the air out and that 2-2500 wasn't cutting it. I will do the same, on an incline

 

Over the course of a couple days, I did the above method twice (revving the bag out of it with the cap off) just to make sure. I have to say I thought I had it on the first day, but the next day i STILL got air out so i'm glad went for it again. No more air in my heater core now! I can't believe how much of a fight it put up