Like the second post suggested, did you properly bleed the air out, this isn't an old tractor that you just dump a bunch of coolant in and call it good.

There is a bleed valve on one of the lines going to the heater core, remove the plug, next SLOWLY add coolant to the radiator, if you are adding it faster than 1 gal per minute you're going too fast, if you go too fast you trap bubbles then the car overheats. Once coolant begins to spill from the bleed valve put the screw plug back in, continue to add coolant SLOWLY until the radiator is full.

Turn the climate controls to FULL HOT with MAX FAN SPEED, leave these on until the system is completely purged.

Start and run the engine with the spill-free funnel installed, once temp begins to climb bump the throttle so you rev the engine to about 3-4k, do this a few times, squeeze the upper and lower hoses, rev the engine a few times, squeeze the hoses, etc. You'll know when the system finally burps because it will suck about 1/2 gallon of coolant out of the radiator.

Have your cap pressure tested, if it's not functioning properly it will overheat but since your lower hose never gets hot you likely have air trapped behind the thermostat, you probably need to drain out all the coolant and start over again since it sounds like you ****ed up the step about adding coolant slowly.

 

It was the thermostat. I got a new one checked it with boiling h2o. It appears to to be cooling properly now but now these lights are on and the car appears to be in limp mode. P2122, p2138 codes

 

Those codes are for your accelerator pedal sensor. I'd start by checking your ground conditions.

 

I am willing to bet you have a blown headgasket.

 

^Hmmm

Care to elaborate, I'm curious why you think that.

 

1st motor i had I went through each and EVERY one of those situations.

Changed:

Radiator as it began to lift from the caps to a PWR full aluminum.
changed caps (5 times)
changed thermostats
removed the bloody thermostat
changed water pump
went from fan clutch to e-fan


throughout all of this I would spend COUNTLESS hours bleeding the system.

at the end of it all i ended up tearing apart the entire engine myself and performing a headgasket job myself. (PAIN IN THE A)

After that the engine ran amazing, 0 issues until I had an issue with a bad motor mount and the engine lifted and dropped quite intensely causing the crank to come off the mains) But that is a different case.

 

Well now, that's a great read. I really hope that's not the OP's problem but I'm glad to see you posting more than normal recently. I love reading your technical posts and seem to learn something new about G's when you do. Thx.