temp gauge up&down normal or overheating?

OK I finalllllyyyyy got my taurus running new radiator etc... now I didnt really drive the taurus before so I dont remember if this is normal or if its some kind of mailfunction...

Anyway after filling up the coolant I started the car, it sucked a bunch of coolant from the overflow tank (2-3 full tanks) now it runs fine but I let it idle in my garage for a little bit and from what I could see is that the temp gauge went up like 1/8 pass the middle mark then the fan would turn on cool it down and then it would go up the fan would go on and so on..... is this normal?

Tom

Sounds like thermostat issue. Did you replace it with the radiator? It could be bad or it might not be the correct opening temp.

What temperature thermostat are you using? Did you flush the heater core?

How do I flush the heater core? ;) I just disconnected the radiator and connected a new one (junkyard one.... ) why would it be a tstat issue? I have no idea what temp it is... but from what i can see... the radiator cools the coolant thats going thru the fan so if the radaitor was in the closed position the car would still overheat and if it was in the open it would never reach to the middle.

Tom

Junkyard radiators are used and may have some obsructions. If possible, after the car has reached operating temp, turn off car, disconnect battery (to keep the fan from coming on). Feel the radiator for any cold spots. Cold spots can be indicative of obstructions.

To flush the heater core: Disconnect the hoses going to the heater core. Attach a hose (4 to 5 feet long) to the inlet and point away from the motor. Using a short length of 5/8" diameter hose with a female end for a garden hose, attach it to the outlet of the heater core and a garden hose. Turn on the faucet and flush it clean.
If you are using a high temp thermostat, it will not open until the motor reaches that temp. When the thermostat opens, it lets the cold water from the radiator into the motor and cools the motor down. The colder motor temp then closes the thermostat.

How are the temp fluctuations when driving? The fluctuations you describe mean that the thermostat is opening and closing and the fan is coming when it should.

Since your car isn't overheating you should be fine.

it only goes up to the M letter then the fan turns on... Ill try to flush the heater core but I tested out something... when the car was warmed up I put the heater on and it worked fine (really hotttt) Which would indicate that there is coolant flowing thru the heater core...
I didnt get to drive the car since I still have to put a few lights and misc stuff on it (involved in a crash).

Tom