leak

I start my car up and it sounds awesome. As soon as I shift the engine gets real quiet and almost sounds like its about to stall. Any suggestions what I can do? I heard maybe something with the carburetor. I am new to this so anything will help/

I am looking at a Chevy Suburban, there is a radiator is the front of the hood, and then on the front of the radiator, is a small narrow radiator, going up and down about 2" wide, and going to the bottom of the radiator (I have a pic) and it is shooting like a brown foamy oil from the loop of...