If the above doesn’t solve the problem, you need to test for hydrocarbons in the coolant. Test kits are available at a variety of places. Another quick, clean, easy, handy tool.

If that comes up false you need to inspect the water pump. There is a possibility that it still pumps coolant but not as efficient and with cavitation creating air bubbles and excess pressure. Hence puking coolant. Yes, a coolant pump can do this without having a bad seal and therefore without coolant coming from the weep hole. If you noticed when you were bleeding/burping the coolant system that the bubbles never stopped and the coolant level never stopped fluctuating; that’s pretty proof positive that the water pump has failed.

You can take the belt off the pump, start engine, and let it get up to temp with the funnel in again. You’ll likely notice no bubbles.

 

Buy something like this:

 

I also strongly recommend a two-stage thermostat.
You can get one here: LCE 2 stage thermostat

That will stop the whole "go up to 3/4 before the thermostat opens" problem. Once again, place it so that the small part is towords the firewall...

I know, it means breaking the system again, thus getting some air in, but it's in a very easy area to get rid of it. Especially, if you only drain enough coolant to get below the level of the thermostat, instead of all the way down. It reduces the air that can get into the engine and intake manifold areas.
I also suggest a new o-ring for it. They're readily available all over the place.

Good luck!
Pat☺

 

Welp I believe I discovered my problem. The radiator has a slight leak but only when thermostat is opening up. Not the best pictures but it is leaking a little.

 

Guess I'm going to have to put the yota in quarantine for awhile 😔. Pretty sure this is gonna be the culprit and worse case scenario. Gonna test before I start the tear down.

 

Is that oil!?

 

If that's oil in the radiator cap, you've probably got a bad head gasket!
Pat♂

 

Haven't performed a test yet but I'm assuming that's oil. I guess the new radiator put enough pressure in the system for it to finally show its ugly face.

Anything else I should check/do while its tore down? Timing chain and such was done about 15k miles ago but so was the head gasket 🤦‍♂️. The truck did sit for a little bit before I got it though.

 

Oil in the cooling system isn't common, and a bit problematic.
Usually the pressure on the water side is greater, which keeps oil from entering. If that is oil you should pull the hoses and see if they have a oily film inside. Oil will absolutely ruin any hose carrying water. It makes them swell up and get very soft. I'd recommend researching how to flush the oil out once repairs are done.
Radiator hoses are pretty cheap, and good to replace anyway, but all those little hoses to the IAC and throttle body, along with the heater hoses, get pricey. If they have oil in them may not be a bad idea to pull off and try to clean.

 

Welp I got the truck out of the shop today. Turns out the head bolts were loose. I'm talking able to turn with fingers loose. Anywho... all new gaskets and torqued to spec again. Flushed and flushed some more because its nasty! I've drove it about 30miles and it hasn't missed a beat yet... I dont quite trust it just yet lol.

 

If you had oil in the water, even after you flushed and flushed, make sure to keep an eye on the water hoses. Check for softness, or bulges. All three of the main ones. Check the little ones under the Throttle Body, and going to the heater, too. At the first sign, REPLACE them. Immediately. Keep a set of the three main water hoses on hand, and at the first sign of anything wrong, replace all 3.
When you do, you can drain the water into a bucket, or buckets, and inspect for any sign of oil. Even a slight sheen of oil on the surface, discard it, flush the system some more, and get all fresh water and coolant.
It all sounds like over-reaction, but it's better this way than blowing a water hose, even one of the little ones, on the highway!

BTW: Just curious, how did the head bolts get so loose?? If a mechanic did the work, don't go back to him. If you did it, be a bit more cautious next time, maybe? As far as I know, there shouldn't be a way for them to work their way that loose on their own, after they're torqued down correctly initially, but I may well be wrong on that.
When I did my head on the 4Runner, I torqued them to spec. They haven't budged since. About 50K miles so far. I never retorqued them, either. I would check for any sign of them backing out, but nothing. A small mark with an awl on the head bolt and the head are great tell-tales

Good luck!
Pat☺

 

Definitely keeping an eye on for awhile. The previous work was done a local shop but I've never used them myself and probably won't ever now.