New info:

So yesterday I "burped" the cooling system, meaning that I put the front end up on jack stands and ran the car with a funnel in the radiator, watching the coolant go up and watched air bubbles go out of the system. After an hour, my car was not overheating and I finally got heat through the vents at idle, which I couldn't get before, so I thought the problem was solved.

I took it off the jack stands, drove it on the highway, and got no overheating problems, but then I came back home and once again had no heat at idle. When I checked under the hood, coolant had leaked or sprayed out in the area of the coolant reservoir. This spray always happens when the car is overheating.

Then this morning I drove to work, saw no overheating on the highway, but when I got close to work, the car did start to overheat, I had no heat out of the vents, and checked under the hood and saw coolant had once again sprayed around near the reservoir.

The level in that reservoir never has changed. Does anyone else think the problem may be in the hose between the reservoir and the radiator?

EDIT: nvm, I just checked the overflow hose and it is working fine. Tastes great too.

If you haven't already, try buying a new radiator cap. When they get worn they don't hold pressure in the radiator and leak coolant into the reservoir. If you keep the reservoir level too high it would overflow and explain the spray that you're seeing.

maybe I can help by telling you my story...

Had a bad radiator (full of dried mud from years of off-roading... long story short, bought a new radiator...

installed, did like you did to fill up everything and right there the problems started ... the truck would overheat as soon as running temp was reached and load was applied or traffic stop n go.

I did the same thing as you , put it on jack stand and fill it until all the bubbles where gone... After , the problem was still there but on a lesser scale... it would take more time or longer run to overheat, but it was..

I found the only way to really get all the air out was this... (what follows is dangerous, but it can be done if you take your time and use protection.)

1) start the truck
2) find an inclined hill.. mine was a good 2 or 3 feet of difference between the height of the rear and front wheels.
3) open the hood
4) let the truck reach running temp
5) ** this is the important step *** once the temp is starting to raise over the fifth bar (this is my running temp since I had the truck in 2009), then you know it has started to overheat... Use protection for your hand (glove, rags, anything), and slowly open the rad cap but do not open it completely- just enough to let the air out. You will hear the air escaping (eventhough you were sure there was none)... Once liquid comes out, screw it back and you will see the temp will have gone down instantly..
6) wait a good amount and repeat if overheating starts again.. (It took 3 times for me). Once you have it solved on idle, go back in the truck, apply brake, put in drive and try to put some load.. You kind of whant to make the engine work harder without having to go anywhere... so the brake pedal to the floor and press the gas in order to see if the temp goes back up. If it does, do the cap trick again because there is still air in there... if not, then you have fixed your issue..

Again, I know it may sound weird, but this is what was needed on my brand new radiator...

Cheers
S.

Looks like I'm dealing with a blown head gasket I was about to try to burp the system last night one last time and checked the oil cap, and sure enough, saw foamy oil around it.

Does anyone know of a good online write up for replacing head gaskets? I know it's in the FSM, I just like to read a couple sources. I also don't want to remove the engine from the car if possible.

Just an update for the 0-2 people who will ever find this useful:

Finally got to the head gaskets the other day and while they don't look like they are in great shape, I don't see any obvious signs of being "blown". They are 3 sheets of thin aluminium with a black coating on parts that looks kinda rough.

I also pulled the "water control valve" and boil tested it. It was caked with residue and did not open at 220F (the highest my thermometer will go). It's supposed to open at 205F. I'll be interested to test it side by side with a replacement unit tonight and see if the boil test shows any difference.