2004. 1500. 4.7 have a water leak that comes and goes it will go a while and not leak anything then it will leak some. But tonight I pulled in garage to change oil drained oil replaced oil filter and put oil in it got in truck started it let it run for about t min pulled it out side went back in there was a large puddle of water were it had been it was not there while changing oil had to do it when I started it went to truck there was nothing where I parked it started it up let run nothing. Does not make sense. The truck leaked a little time to time nothing like this. We have pressured test it a couple of times hold pressure just fine left it on for two hour held steady. Any thoughts. Thanks

Did you have A/C on?

That is what I was thinking AC condensation.

Is the fluid level low in the radiator after spotting these leaks?

So, I had one of the Dakota plastic tank, aluminum core radiator in my 49 Dodge truck. That radiator had an intermittent leak that would come and go, sometimes not leaking for more then a month, then leaking out a quart of coolant in a couple of days.
It took months to find it.

What I was getting was a leak at the pinch seem between the plastic tank and the aluminum core. At very specific temps (about a 10-20 degree swing, half warmed up), the pinch would open up (didn't matter if the temp was increasing or decreasing), then when it got above or below that point, it didn't leak.

In hot weather, it barely leaked at all, probably because it went past that point so fast. As the weather cooled, the leak was worse because it took longer to get past the specific temp. It never left any trail, and if I hadn't actually seen it leaking one day, I probably would have still been looking for it. Once the radiator was out of the truck you could see the signs of the leak, but you sure couldn't see them while the radiator was still in the truck. I replaced the Radiator with a complete aluminum radiator. Haven't had a problem since.

It is coolant. Now today did not leak a drop and I looked everywhere I parked and it was in the 90s don't know kind of puzzling. I will keep a eye on it like I have been. When it leaked after the oil change it was a pretty good amount not a drop or two. Thanks

Coolant overflow recovery tank (or hose) cracked?

My 2001 Dakota (4.7V8/5spd manual) now has 203,000 miles on it and still starts right up, idles fine, and no leaks other than the steering reservoir drains down quickly, so I know there is a leak somewhere in the steering system. No oil leaks, no tranny leaks. But it does burn some coolant. The coolant color has never changed, the oil has never become frothy. But it definitely uses coolant which I suspect is a head gasket issue that is allowing coolant into some cylinders. Every once in a great while I'd also get the coolant smell in the cab. The early 4.7s were known for coolant use, so its a fact of life with this old engine. My Dakota chassis is the eventual donor going under my 56 Dodge pickup, but for that build I have a 5.2 Magnum V8 coupled to a 8HP-70 8spd automatic, so the 4.7 will go bye bye to the salvage yard even though it is a decent runner. Not worth rebuilding or modding as I can get more for less cost hopping up the 5.2.