Overheat battle

Evening all,
This is a long one but I will try to get everything in one post to minimize redundant suggestions. Hopefully, someone will save the day (and my truck).

I recently bought a 1996 Toyota Tacoma 2.7 4x4 with the 3rz. I found it while in the Middle East, and drove it from Chicago to my base in Texas. Had absolutely no issues. Since then everything was going stellar, until the radiator cracked and spewed rusty coolant all over my engine bay while on a 3hr trip. I didn’t notice until I got home as it did not overheat. I promptly flushed all the bad stuff out through the old radiator using the t-hose diy kit from the parts store, until it was clear. I then replaced the radiator, thermostat, up/low rad hoses, and cap. After road testing it the temp gauge on the dash showed it was overheating.

Below are the actions/tests I’ve taken to no resolve.
Tests:
Combustion/exhaust in coolant✅
Pressure test✅
flush x2
Parts:
Radiator
Thermostat x2
Fan clutch
Hoses/cap
Air filter
Plugs/coils

Dash temp gauge only shows over heating when I slow down or idle after driving and goes back to middle when I drive again. I use a repair solutions Bluetooth diagnostics reader and it shows anywhere between 190-220 (lower idle, hotter driving)
Yes, I have heat. No I’m not losing coolant.

I hope this covers everything, thank you all.

 

Did you purge the system of all air?

 

@Nessal yes on incline

 

A slow head gasket leak is hard to diag, combustion enters the cooling system under load. It also causes a stumble misfire in the morning sometimes.

it’s possible there’s still air trapped causing this, I’d bleed it again as a precaution.

While bleeding watch the coolant while revving, if there’s combustion you’ll see tiny bubbles trail up. I find the tool stores combustion testers don’t work that well on Toyota unless it’s truly blown.

just ideas

 

Silly question....did you put the thermostat at the 6 o'clock position?

 

for the 4 banger its at the 12 position, no?

 

I'm suspicious of your water pump. If its not flowing coolant like it should, you would experience all of these symptoms.

How many miles are on this thing?

 

@KdF jiggle is at 12 per service manual, I kinda wanna try it at 6 though.

 

170k @0xDEADBEEF

 

@Bishop84 no bubbles and no white smoke out of exhaust