Hi folks!
We have a 2004 Ram 1500 with the 4.7L engine, 65K automatic 4WD. VIN #1D7HU16N24J139102 if that helps... Bought used some 5 years ago, works as a landscape mow truck, towing a couple of z-mowers at most. We had to rebuilt the LS differential the first year, and replaced the timing chains last spring. Ran OK aside from misfire codes every once in a while.
Last summer, hauled up a long hill just fine and parked on the side of the road. Went to leave the job site and the truck started easily, but ran very rough and weak -chugging like it might stall out. Limped home, and while we had our heads under the hood trying to find the issue someone slammed a door and it started to chatter/tap...
Popped the valve covers - lifters are all OK. No discernible metal bits in the oil. Replaced plugs, checked coils, seem OK. Was running very hard and started to rev out so we killed it and hauled it to a local back street mechanic who said he reconnected a few vacuum lines so it ran better, but motor is done.
It's been sitting in a corner since. It systematically drains the battery - I can hear a purring noise in the dash when it is off, that won't stop for hours, until all juice is gone. Starting, the headlights flicker even though they are off. It will run, ticking, for a few minutes, but eventually stutters, idles down and stalls.
It is low mileage, paid off and in good overall condition, but mice, disgruntled ex-employee mischief and total computer meltdown are all possible - we'd like to be sure the motor is indeed toast and it isn't something else stupid (and maybe cheaper). I can get the codes later, but other truck issues taught us that codes are clues, but can also point in the wrong direction sometimes.

 

Do compression check? 4.7 are notorious for head gasket if they get hot. Ticking can be a exhaust leak.

 

3 things to replace, and use factory parts not aftermarket, throttle positioning sensor. camshaft sensor and crank shaft sensor, one of these is not getting correct voltage to do its job. these are the main component's of the fuel electrical system, when ones says I don't want to work today. the others struggle. also a new battery. you could have a bad cell in the battery now, as for the drain, start pulling fuses until you hear the noise stop and pinpoint the issue. Maybe a stuck relay.

 

That purring noise is the motor for your fresh air/recirculate door. They typically break, then the motor just turns because it isn't registering the resistance that normally would occur when the door reaches its seat. It doesn't know to turn off.