99 dodge 1500 p-up-318 block starts fne, warms up and starts to hear air suction sound from under the hood, motor kills and then wont stay started after that...

have a look under the hood, and inspect the vacuum lines, possible one got disconnected causing your issues.

Sounds like tappets valves or cam bearing ?

This is an interesting fault. The click you hear is the relay, that puts power on the starter motor, but you do not hear the starter motor turn. (Or do you?)
First suspect is the battery, they do get old and tired, but you say after a while it cools down and starts, so its probably not the battery. Check the cables to and from the starter motor, and the fat earth cable from the engine to the body (in the engine bay) make sure they are undamaged, clean and the connections are not loose. IF all looks ok I suspect the starter motor. remove the starter motor and clean it.

If the hissing is coming from under the hood,you have a vacuum leak at one of the hoses,EGR valve on top of the engine, or a hose off someplace like the line going down to the transmission. An easy method to check where, is toget a can of spray starting fluid, and spray a tiny bit in a few places around the engine. When you hear the engine rev up,your very close. If the hissing is inside the cabin, check the hoses at the climate control or the blend air door motors.

sounds to me like the starter motor solinoid has gone so you need to replace the starter motor

if this helps please let me know
cheers
big mike

if u can try and take a the heater core hoses off under the hood and take a water hose and run water thru the heater core on both ends the in and out cause there could be junk in there causing it not to flow properly

battery is dead again let it charge longer then try it.
clean your cables and then have the alt and battery checked if they are both good then something is staying on like mine my brake lights stayed on once and killed the battery
good luck

If on either heat or AC your not get'n any air out of your vents but can hear your blower motor turning then i would say you need to replace your cabin filter.. it filters the air inside of your vehicle

Check all fuses under hood , in that power distribution box, (usually near battery,you should find a label under cover to show you where fuel pump relay located.

It sounds like the fuel pump try banging on the fuel tank with a block of wood while someone else attempts to start it. if it starts after a couple hits its the pump if still nothing check the relay under the hood