Thread: A few issues

Hello all. New to the forums.
Lately when I am sitting at a light my temp gauge goes right up to 210 degrees. As soon as I start moving again the temp goes down to normal.
A couple of weeks ago my 97 3800 se (54k miles) starting over heating. I Let it cool down, pulled off the radiator cap and there was a 1" thick chocolate mousse looking stuff going into the radiator. I scooped it out with my finger and added anti freeze. It took about 3/4 of a gallon to fill it back up. Now here I am and the car is running hot again, I check the radiator and it is low again. I have not seen any water leaking in the driveway or anywhere else. The car never actually gets above 210 because as soon as I start driving the temp goes back down. I check my oil every week and I have not had to add any at all. Also, I have noticed the past couple of weeks that there a squeal under the hood that starts up after a few minutes of the car running and does not stop. It is coming from the serpentine belt area.

Any ideas what is causing these 2 problems. I plan on having an oil change and a radiator flush today.