Coolent leak
seville009 has the right idea. Before you start throwing parts at it (prices range from mild to wild depending on what you replace) start with a clean slate and let it idle for a bit (parked), see where the drops fall, and go from there.
I don't know anything about your truck (condition, driving duties, what you've replaced in the past, etc.) so I'm just spitballin'. Based solely on the pictures the first places I would look would be:
- The water pump. I'm not sure how many miles are on your truck but it will wear out. There's a weep hole on the bottom of the pump (that drains above the harmonic balancer) that will start to drip as the internals wear out.
- The lower hose and connection. If you don't have any coolant seeping from above the water pump this would be the next place I would check. Many people replace hoses, thermostats, and the thermostat housing (upper hose connection) on a (semi-) regular basis as part of a maintenance schedule. The lower hose connection is also bolted to the water pump just as the upper one is (thermostat housing). Being on the bottom subjects it to all the road grime which doesn't help it as far as lifespan goes. Check to make sure that the connection to the pump and the connection at the hose are not leaking by. When the system is not operating (~16 psi) there's 8 gallons of coolant/water mix in the system and most of it is above that connection. This provides a static head (pressure from the weight of the fluid) on that junction which will weep through any imperfections in the seal.
I'm not sure if your upper hose goes around the serpentine belt or through it. If it goes through it, and you drain the coolant to fix your leak, I recommend getting the upper hose that goes around the serpentine belt (it's the hose for trucks with dual alternators) so that you don't have to pop that off the next time you remove the belt.
Again, those are just my ideas of what I would do based on the pictures. Hopefully it helps some.
Best of luck and let us know what you find.






