This has been a real good thread and I think ol' firebird got his problem fixed. You get to learn quite a bit about a lot of things when it comes to cooling systems. I did notice a couple of bits of small misinformation though. All computer controlled cars do not kick the fan a 226, this number will actually vary from maufacturer to manufacturer and from model to model. Some Asian imports kick the fan as low as 212, a good tidbit if you are runnin' a coolant fan swithch and want you fan to come on at a lower temp.

I don't like my cars to run much over 180, but many cars do and will run at these temps. I drive older cars, newer cars designed to run on unleaded can and will run as high as 225. Example, I had an '85 Iroc Camaro, TPI 305. That car would hardly come down from 220 - 225 and it always made me nervous. It never overheated and always ran great, so in reality, no problems. I also had a '79 302 Mustang that ran way up there, right at the tip of overheating, scared me to death, never overheated and always ran great. My Blazer, 2wd, 350/350 really likes it right at 180. I can hardly get it any warmer, even with bigger thermostats. I guess I really don't want it any warmer, but temps can and will vary some within these numbers, depending alot on the car itself.

Water Wetter does work very well, Royal Purple also makes an additive that works very well. I would suggest it to anyone who is having problems with heat.