It would be much easier to pull the oil dip stick and would tell you the same thing as cracking the oil drain plug.

A cooling system pressure test
should not break the bank.

I recommend this rather than throwing cash.
You'll need the money if a head gasket.

On some of the GMs I burped em from
a bolt (plug) on top of the thermostat housing.

Yes, diagnosis and troubleshooting first, before shotgunning parts at it, is the proper way to proceed.

While you where refilling did you do it with the engine running or turned off? Turned off you trapped air in the upper head. Did you replace the cap after refilling, pressurizing the whole coolant system? Vapor locked the engine, so locally the head gasket could be cooked and it doesn't necessarily have to leak on the ground, leak into the oil, could be leaking into a cylinder/s being vaporized during combustion. Always better to run with little load and slow without the radiator cap so as not to pressurize the system under those circumstances. A pressure leak significantly raises coolant temperature and head temperatures.

Well, we're gonna drive it today about 60 miles and see what happens. Wish me luck, lol.

Just gonna send it!

Good luck, hope it was just an air pocket that burped out. At least take a jug or two of 50/50 mix with you.

Yes, I had the vehicle turned off and yes I put the cap back on. You're not making me feel better here.......

Not necessarily, the dip stick only enters the top 2 quarts of oil or so, doesn't reach to the bottom of the pan where any water would be found. Only thing the dipstick may tell is if the total volume of oil and any water is high in a cold engine.

The water pump is run by the belt. Losing belt lost the water pump. Without the pump moving coolant through the radiator to cool it, the collant boiled off in the head of the engine. This means the head got very hot (regardless of what temp gauge says - the temp sensor is probably at the coolant outlet, which is representative when the coolant is flowing - not when the pump isn't running and coolant is boiling in the head).

At this point the hope is that the additional coolant loss was just a bubble of air in the system and it won't take any more coolant.

But being hot enough to boil off coolant means it could have easily been hot enough to warp the head. If that's the case, coolant will keep disappearing. If the coolant is getting mixed with oil, the engine won't be running for long. If the coolant is getting burned (leaked into the combustion chamber), it will likely get worse over time, but... A bars leak seal product (or similar) might fix it for a long time if the leak isn't very big and OP is lucky.

Continuing to drive it while leaking coolant is risky. At some point it will get too hot. One way or another, the vehicle wont' be in this situation for long.

I think you warped or blew a head gasket. It done so no since in saying what you should have done. I think with all the water in it. It is burning the water off and not showing in the oil. If it was anti freeze the oil would be milky.

When an engine is run with water in the oil, it gets mixed up and that is what give you the milk shake look. If it is leaking in with out being run what you say could be true. But once it is run it is mixed and will not separate much.

Ive got one 2014 5.3 Lt rough idle little bit of smoke at start up not loosing coolant but getting hot oil isn't milky coods show its both to rich and to lean in bank 1 and 2 and passenger side cat isn't running efficiently (per code reader)

Well I don't know for sure yet but I think you may have nailed it.

What I did not mention in the original post because I didn't think it was related was that around the same time........the engine started running rough at an idle. But not when driving regular speed as far as you could tell.

So, Tues. I made the 60 mile trip. No issues with getting hot at all. But the check engine light came on. I read the code. Missing on Cylinder #1.

Ok, no biggie I can fix that... I think. Well turns out I couldn't as you have to pull the exhaust manifold to even access the plugs/wires.

So I checked the water when I got home that night. It was full.

Yesterday I made the 60 mile trip again. No issues with getting hot. By this point I am thinking the guys saying it was a bubble were correct.

Today I drive 30 miles...no issue. Leave to come home and within 5 miles it was getting hot!!!

Stopped right away and added water.....it took over a gallon!!

Drove it to the mechanics.

So now I am leaning towards what you said Scott. I think the head gasket IS blown and it's leaking into the first cylinder causing that misfire.

I should know what's going on by tomorrow.

Blown head gasket in the Nissan 2.5 is very common. That’s where I’m guessing your problem is.