This is a how to to find out if the head gasket is leaking combustion gasses into the cooling passages.
Disregard the rattly noises, bad bearing in the power steering pump.
Here is the Tester I own and use, but any shop will have one, or any of this type will help.
The blue fluid when in contact with the carbon-monoxide (I believe is the gas that does it) turns green if just a small amount, or yellow if large leak.
https://www.amazon.com/UView-560000-...on+Leak+Tester