Dissapearing Coolant

I have a 98 Blazer 3.4l V6

I been noticing lately that my coolant reserve tank keeps emptying.

I've noticed no leaks. I replaced the termostat, radiator cap and I filled the reserve tank with the dexcool/water mix. After about a week or so, the tank is empty.

I'm really trying to avoid brining it in for a pressure test to test for leaks, so any help would be appreciated.

Why avoid testing?
Which is cheaper testing or a new engine?
If you can not see the leak you need to start pressure testing and checking for the leak.
Before you blow it up.
Any engine miss on a cold start or blue smoke out tail pipe?
Is the engine overheating?
Watch the oil real close for coolant in it.
Another aid in finding the hard to find leaks is adding coolant leak test dye to the coolant. And putting the light on it.
And check a sample of the engine oil for for dye or coolant in it.
MT

I'm avoiding putting money into it because this POS is being run into the ground. It is at the point where it is not worth it to put money into it because of various problems I have/had with it and it will be cheaper to get a new car. I want the cheap fix to get me through a few more months before it is junked.

No missing.
No smoke.
No overheating.
Did an oil change recently and it was pretty bad, but I blamed it on being 6month old oil (though it was only driven 2000mi since the last change).

First thing would check and find the leak.
It could be as simple a tighten up a hose clamp or as bad as head gaskets or intake gaskets.
The only cheap fix is to grab a wrench DIY it.
A lot cheaper and better Fix it now or park it or trade it now or junk it.
If you keep on driving it like that it could blow the engine or drop any time.
Then what kind of trade in would you get??
Your choice.
Good Luck

I don't care about trade in.

At this point, it will be brought to a field where I can go to town at it with a baseball bat then dropped off at the junk yard.

No point in me putting in all this money at a shop when I wouldn't even get that money back selling it or trading it in.

Oh yes, and you only have one of them!
Classic is the lower intake gasket sprays coolant into the valley of the engine and it burns off so never see it in the oil - usually get a morning lifter tap but this will take the engine out at some point as there is a balance shaft in there, the cam bearings, and lifters. Understand your opinion. Most leak by around 100k miles.