1998 Buick Century

Noises problem
1998 Buick Century 6 cyl Front Wheel Drive Automatic 100000 miles

Tonight when I got home from work - I pulled into the garage and turned off the car. Before I got out of the car I could hear a loud noise - it reminded me of a pan of water boiling on the stove - loud bubbling= banging noise. I lifted the hood but could not see anything. After it cooled down I checked the coolant which was at the normal level, oil normal level. I did not notice it overheating when I was driving but checked it when I moved it out to the driveway, it was only one mark past the middle mark. My a/c is out and of course we are having hot weather. Could it be air trapped in the core?
I was filling my coolant resovoir all the way, but I ran out of coolant, and haven't bought more yet. Could over filling the resovoir cause a problem? Do you have an idea of what I should do or take it to someone?Thank you for your help. Deb
September 10, 2010.

Most likely the noise you heard was the coolant in the expansion tank. You most likely have a 3.6 or 3.8 engine, and they are known to blow intake manifold gaskets. Such as the 3.1, and 3.4. However if you have a 3.1 or a 3.4 in this car, I strongly recommend head gaskets also, as there is a bulletin on those.

Sep 10, 2010.