heat just isnt as hot as it should be only gets to luke warm, ive changed the heater core thermo and flushed entire system its full of coolant.?? wat else should i check?? All the lines feel hot so were is my heat???

 

I'm having the same problem...but I just changed my waterpump and thermostat...instead of heater core...

 

Run the car through a couple of heat cycles and try re bleeding the cooling system. Eric L

 

update- kinda fixed the problem put a diff thermo in it and gained alot of heat back, (possible bad thermo) dont know but i have heat again or at least ill test it soon when it gets cold

 

how much coolant comes out the thermostat housing when you took it off? I want to try a thermo swap too (even tho mine is brand new)...but since I was changing my WP, the system was already drained. Just dont want to pee on my brand new opti..lol

 

Are you using the correct "LT1" thermostat?

Courtesy of Shoebox:

http://shbox.com/1/tstat.jpg

 

very little came out of my houseing but i was very slow and careful about it. easy as pie to do. And ya the one i took out was the correct thermo im thinkin it was stuck open because the new one helps my motor warm up alot faster.

 

just make sure you get ALL the air out of the system, the heat will work.
i have a 160 in my car, and it gets nice and toasty in there in 30* weather.
i had your same issue, but i bled the system real good, and works wonders.
if you can, i used flow controls with quick disconnect hose fittings on the end so i can hook a 1/4" hose to it and run it to the overflow bottle.
one time i hooked both them bleeders together, and pulled a vac on it an let it drain for 30sec-1min at a time with engine off, and all the air was gone (that’s how i got the best heat i have).

aaron