Clean out the crap between radiator and condenser!
I've been reading all the posts about every thermostat temp from 160-200+ deg. what works and doesn't.
Having been about 10 years since I last replaced my radiator (although I do flush it myself or have it power flushed every year or so) I decided to pull off the radiator shroud just to see how much crap was there!
Boy!
As one other forum member said..you find everything in there!
No wonder vetts can't get cool or stay cool ever on the highway!
I pulled out shredded plastic grocery store bags, leaves, newspaper, pine needles...everything but the neighborhood stray cat!
So before you start to change out the thermostat clean out the crap!
I blew forward with compressed air thought the radiator as well as AC condenser as best I could.
I also drained out about a gallon of very green coolant from the radiator and replaced with clear tap water. Then added some of the green coolant i drained out back into the overflow tank ..just in case. I think my pure water to antifreeze mix was excessive on the antifreeze!
I started the car, AC on, radiator cap off and waited till the 180 thermo kicked in then gradually adding clear water till it was full while circulating. Put back on cap and good to go!
I have had a chip installed to turn on the main fans lower temp, 180 thermo and 200 on/185 of aux fan switch setup for several years now.
It was working great till over the last year or two the coolant temp was gradually getting higher-even after last summer power flush.
Now my around town as well as highway cruising temps are about 15-20 degrees lower than previous. Outside today in TX around 92-around town about 200-205 driving in traffic. Let the car sit idling for about 15 min. talking to a friend and it got up to about 215 but never warmer. Freeway about 70 MPH was right around 200 daytime and 188 at night with the AC on always.-day/night.
I think my problems were I had too much antifreeze in the system as well as the big problem of crap between the radiator and condenser.
I did bypass the throttle body yesterday too but I doubt that had much effect on the overall picture.
Just F.Y.I. for those having some cooling issues this summer!