why does the engine bay smell like coolant but has no visual leaks?

What is your question?

after the truck has been run for like 10 minutes it smells like its leaking coolant out of the reservoir but I don't know iv looked everywhere it's not leaking from the timing cover but it could be the thermostat but it's not a head gasket because it's not burning blue smoke from the exhaust

What makes this problem better or worse?

its the same every time

How long has your 1994 Ford F-150 had this problem?

a couple weeks