92 Sunbird Overheating?

I have a 1993 Pontiac Sunbird (4 cyl.). After I start the car with the engine totally cold, the temperature gauge will climb into the red zone before it suddenly drops back down to normal temperature. After the initial climb to the red and drop in temp, the gauge will settle into a cycle of climbing and dropping, all in the lower 25 percent of the guage.

I replaced the thermostat and radiator cap. (The thermostat is under the radiator cap.) There is a slow leak of fluid where the filler tube meets what looks like the water pump. However the fluid level is okay.

Any suggestions? It seems like it runs fine after it reaches the point where it is about to over heat.

Chris

 

See if your heater works , basically you want to make sure you have water flow, 1993 model I'd change the thermostat and cap no questions asked, the engine you save maybe your own

 

Sounds like you might have some air trapped in your system. Follow coolant "burping" procedures to eliminate any air pockets.

 

The thermostat should be where the radiator hose enters the engine block. It sounds like it would be the thermostat or the heater core. It could also be air in the system. leave the cap off and start the car let it warm up, see if the water drops or starts moving fast then the themostat is probably working. I am only guessing but I hope this helps you.

 

sounds like it wasnt burped

 

I believe you are referring to the overpressure relief spring under the radiator cap. Like stated above trace top radiator hose back to engine and there will be your thermostat housing with a couple bolts holding it on.

This guy below has mad autozone.com skills

 

It sounds like the thermostat to me also. It's not under the radiator cap, but where the upper hose attaches to the engine, again, as stated above.
Go to this Autozone site for full instructions.
http://www.autozone.com/servlet/UiBr...3d800effa9.jsp

 

it probably is thermostat causing the temp guage to enter the red zone and you might consider trying another thermostat might even suggest a cooler temp thermostat if one is available.
it is also possible that it isnt overheating at all and is functioning normal and the guage could be reading off its not uncommon for the temp of the engine to get to about 230 before the thermostat opens for the first time when an engine is started cold but generally levels out afterwards the cooling fan is designed to come on at around 230 degrees but will usually only reach that temp when the vehicle is not moving and is totally reling on the cooling fan to get air through the radiater which can also cause the guage to fluctuate some as the fan kicks on and off.
the thermostat is under the fill cap on the thermostat housing it is sometimes called a radiater cap and is where the car is usually filled with coolant it is on the link goldstar posted atleast it is very easy to change.

 

Im assuming u kno the problem is ur head gasket and head right :P my 92 did it as well..
I replaced the temp.. and it stopped showing it to be over heating and then all of a sudden.. it red lined and blew a
rad hose and my life was hell I dismantled it and found a sever crack in the head gasket and so I took the thing apart
and replaced the head as well :P can u tell Im ambishis.. and have no idea how to spell ??
so now the thing run like a dream and no problems since...

 

Ten month old thread; no doubt it's fixed or sold by now.