I need to add coolant to 2000 dodge caravan, what kind do i use.

Terry, Add coolant to the reservoir located under hood, mounted by shock tower and fuse/relay center, fill to the full mark on side of coolant reservoir when cold, recheck after running and engine cold again. Check the attached links,instruction and guides, Good luck
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Both if so equipped (has a radiator cap). First top off radiator, then run to operating temp and add to reservoir until at the proper level. Test drive several miles, recheck reservoir.

Most reservoirs are plastic and have a pin in between both reservoirs remove pin and pry up on and off.

Could be a faulty thermostat, low coolant, or a faulty blend door under the dash.

oil is 5 quarts and coolant preston 50/50

i suggest you purchase a suitable coolant and put some in your reservoir before it begins to give your engine problems

this van takes a pink long life coolant, typically referred to as "dexcool".

Check your coolant reservoir under the hood. Your water/antifreeze mixture is probably low. If it is like many other Dodges the smart design of the coolant system on the van causes a low coolant condition to first starve the heater core of coolant before the level gets so low that you overheat and hurt your engine. Likely you will have to add coolant a few times before the system gets all the air out of the heater core and engine caused by letting it get low, so check a couple of times a day until the coolant level in the reservoir remains at the Max Fill line when checked a few different times. That will signal when the system has removed all the air from the coolant system.

its a pitcock facing the cab bottom of the radiator, plastic flat. once you find the pitcock just put a bucket underneath and turn it.then refill. if you want to flush(run fluid thru to clean it out) the radiator id suggest taking it in. you dont have to flush it every time you change the coolant out.