I have a 1992 F150 with 5.0.
I have noticed that I am having to add water on a regular basis. I have no puddles under the truck. No leaking radiator or hoses that I can find. I have seen steam for a few seconds after I shut it off. This afternoon I let it run for about 15 minutes and after turning it off I could hear a hissing coming from around the exhaust manifold area on the passenger side.
I see no signs of water in the oil, truck runs great.
So I am assuming it is either a freeze plug or head gasket.
Where and how many freeze plugs does the '92 5.0 have.

kunder54