Engine overheating

I don't know if the radiator fan works, I guess I am trying to figure out everything I need to check. I usually have a mechanic, but he is sick, and I am trying to do a little homework before I take it somewhere. The car will turn on when it is hot, but if it goes in the red while driving, it doesn't have very much power, but after a few seconds it will run just fine. The new mechanic told me possibly intake gaskets but said it's a big job. Another mechanic told me it's just the temperature guage and that's an easy fix.

Thanks for this post I did the guide and found a blown head gasket is causing my problems.

My car is overheating I have a 05' Chev Monte Carlo

Thank you

My 2005 Monte temp light comes on when I drive in town. It goes off when I am on the highway.

Engine overheats when I use the AC.

Fans seem to be running, but when the AC is turned on I hear a lot of clicking and the idle goes up and down. Also having trouble logging in and out.

Yes it is a 3.4 motor. The clicking is the AC compressor cycling on and off. The fans are running but do not seem to change speeds at all. Did not find anything blocking the radiater.

OK I just went out and checked out the fans behind the radiater. The one on the passenger side spins freely. The one on the drivers side does not spin at all.

I had a hose blow going down the interstate so I repaired it on the side of the road and drove to the nearest auto parts store to get a hose. Before the hose busted the heat stopped working but the car was not overheating, but now the car is overheating and there is no heat coming out when I turn the heat on even though I have changed the thermostat. My brother was putting a bunch of stop leak stuff in it because the radiator was leaking, but we replaced it and I have flushed out the heater core.

I believe that is the problem. Thanks for the help. I remember having that replaced last october, I'll check to see if it is warranteed. Thanks again!