What type of antifreeze do i use? It looks like it has a blue or green color in it.

unlikely
the pump is steel or brass impeller with carbon on ceramic seal
all it does is circulate water
most antifreeze is ethylene glycol based for the majority of cars and are green or yellow
different styles use organic acid GM ( orange or salmon color) is organic acid coolant
forums state that orange and green should not be mixed as the coolant goes to a gelatinous mess that will cause overheating by it will flush out in a professional shop
so if the antifreeze is ethylene glycol base regardless of color it is ok but if the added anti freeze was orange , pink, or salmon color , the you will have to have the system professionally flushed

The orange antifreeze is dex-cool which is suppose to be better, like comparing synthetic oil vs standard oil. It helps extend the life of the antifreeze. Now they have an ANY COLOR ANTIFREEZE that's green, so as long as its that type then you should be fine. It only helps extend and protect the corrosion factor of parts on the engine. hope this helps

take to mechanic ,blown gasket or cracked blockor casting,major problem don't drive, will damage motor or seize up! water jacket in engine could be compromized

it is dex-cool usually orange or red

Use a 50/50 mix of antifreeze and water. You can go to any auto parts place and purchase the pre-mixed 50/50 blend to put in the van. The next time you look in the coolant recovery jug on the van, you will see the color of antifreeze. (Do not purchase a pink antifreeze and mix it in with a green antifreeze) Stay with the same color you have in the van. Hope this will help you.

Pink or Blue.

I'd recommend Preston antifreeze, manufacture recommends a 50-50 ratio of antifreeze and water

check the color, green,blue,orange,red, but watch colors closely and if worse case scenario take a sample into your parts supplier and he can tell for sure which type you need per year of vehicle some have silicon silicates in them some dont, the green/blue arent so critical, but dont mix w/red or orange or you will end up with a radiator full of unset "jello"---sounds funny, but its not,then you'll have serious issues...good luck

im very soory to tell you i think that the head gasket went.and the knocking means your motor is no good.

www.installer.com as speaker schematics