Let us not forget, however, that in this case the engine was overheating before the T-stat was removed.
I think this one has multiple problems at this point.
Assuming a lack of certain tools, the OP might consider dropping the old thermostat in a pan of water and bringing it to a boil.
About the time bubbles start forming on the bottom of the pan the thermostat should start opening to some degree. That’s somewhat of a crude testing method but it gets you into the ballpark.
I also agree the T-stat needs to be in place. That would work in the old days without much of a problem but not so much on modern cars.
i did some work on my cooling system and had a bit of air in it and i got a code for taking too long to reach operating temp. but it was a dodge. dodge engineers are pretty smart. maybe not all cars have that code in their bag of tricks
Alright so an update…I changed the Temp collant sensor, Added a new thermostat, and changed the radiator cap (Old cap shot water out when the hose was firm and I squeesed it) and now the vehicle runs without overheating.
On an 02 impala though I need to know this…Should the temp stay steady?
See my gauge now shows the needle moving between half and 1 quarter of the gauge (It starts at 140 and goes to 260 with no numbers in between) And some times when I have been cruising for a while at highway speeds it will go passed the half way mark on the gauge but it always slides back to the half way mark or better. Is this normal or Do I have more problems to deal with ?
The gage should be steady at steady speed with the engine warmed up. At highway speed the gage should be at the normal halfway position. You could have a partially plugged radiator. If I had an 2002 car I would definitely have the rad flushed out or least inspected for restricted flow.
@Tuku
In my opinion, it sounds like your problem is now resolved
You’re pretty sure you’ve burped all the air out of the system?
Got nice toasty air coming out of the defroster vents when it’s warmed up?
thats a thing the heater blows cold when i idle and just warm in motion.
and yes ran it fo 15 min with the radiator cap off and heater running to get the air out
@Tuku
When the engine is up to operating temperature . . .
Are both heater hoses hot . . . ?
Yes both hoses are hot and very firm
It sounds like you’ve fixed some of the problems, but at least one problem remains. On the gauge question, I can’t speak for the Impala, but my early 90’s Corolla, after a cold start and driving it for a while, the temp gauge moves in an orderly fashion from cold to around 190 degrees, then pretty much stays there. It doesn’t go lower than 180 degrees once the engine is warm. But it will go a bit higher during extended idling. Around 200 degrees the radiator cooling fan kicks on, and brings the gauge back to 190 degrees.
I’m in a mild climate. Seldom do temps go below freezing. In really cold weather maybe the gauge would dance around more on the Corolla.
One fairly easy thing you might consider is remove the hose (at the engine) that connects from the engine to the firewall for the return of coolant from the heater. Leave the hose that carries hot coolant to the heater as is. When the engine is running, even at idle, there should be a significant flow of water out of that hose. Is there? Edit: Do this with the heater on full hot.
Edit: P.S. Are you certain you are bleeding the air out of the system per the manufacturer’s recommended procedure? Every car is differently configured. I wouldn’t expect an Impala’s cooling configuration to be all that unusual, but sometimes a design compromise can be made that requires a special sequence of events. If you can secure a shop manual, visit your local library to see what they have, subscribe to AllData (it’s just a small yearly fee if all you need is the data for one particular car), that would probably be worth the trouble so you know you are doing the air bleed procedure correctly. Your symptom is consistent with a little air remaining in the cooling system.
When you idled the engine for 15 minutes with the cap off, and the heater on “hot”, did you do that with the front end jacked up at all, or on ramps? Sometimes doing that is necessary.
Ill have to check that tomorrow …
“Old cap shot water out when the hose was firm and I squeesed it”
I mentioned this in the seventh response of this thread.
Strange things can happen if the rad cap keeps the system from pressurizing.
Yea and I forgot about people saying that until I saw water shooting out of it 
If I could squese the hose and do that it definately wasnt holding 16 lbs
Tomarow I have to get some actual coolant (Had water running in it until now) Ill flush the radiator and fill it up with all 50/50 coolant see if that changes things.
seems like the problem is not solved if the temp gauge goes to 260f and back to normal. we have owned 1/2 dozen gm cars. i would say all had a temp gauge that slowly moved to “medium” and never went beyond. i did coolant service in all of those cars and dont ever recall a transitional, settling down period while the coolant level stabilized which coincided with an erratic temp gauge
@Cavell I think Tuku was referring to the markings on the gauge when he mentioned 140 and 260 with no markings in between, not where the pointer was pointing. I did a double take on that one. He also mentioned the pointer was going past halfway then settling back. I think it depends on how far past halfway it was going before settling back. @Tuku Can you let us know how far past halfway it was indicating?
This all sounds vaguely familiar. I did pretty much the same things that Tuku did with similar results. Ultimately, the problem got so bad I couldn’t drive 15 minutes without boiling out a gallon of water. At that point I knew it was the head gasket.
Fixed that and the problem went away. I strongly think that is what Tuku is chasing.
Tuku, straight water has a lot of surface tension which interferes with the transfer of heat. One of the things that antifreeze does is break the surface tension so the cooling system works more efficiently. Replacing the water with the correct mix of antifreeze and purified/demineralized.distilled water should correct any remaining issues.
Water only worked back in the old days because cooling systems were 16 to 18 quart capacity. Today, they are only 4-8 qts.
Pure water is a better heat transfer agent than 50% antifreeze. To get the same heat transfer performance from 50% antifreeze, you’d need to increase the flow by 14%:
http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html
The only way pure water would cause you to overheat is if it starts boiling in the engine. Corrosion issues can be severe with pure water.
Not to mention winter freezing issues 
insightful, both you and your website are confusing specific heat capacity with heat transfer between mediums. Your website does not address the heat transfer between mediums, only the moving of heat in solution from one place to another by the movement of the solution. Antifreeze increases the efficiency of the heat transfer between the metal and the solution.