I have one of my 2000 yr TJ's losing coolant, but there are no visible signs of leakage, rad, water pump ,thermostat, rad cap have all been replaced. Still problem exists. This is on a 4.0 engine with approx 84,000 miles. Maint is regularly performed. Any help?  

Forgot, other than removing the head and having checked out, anyone having or had same issue?  

What does your oil look like? Is it milky?  

no, thats the killer. no oil in coolant and no coolant in oil. what I'm guessing is a possible small crack in the combustion chamber which is burning it off ?  

that's a possibility, have you done a presure test on it? also the coolant can be tested.  

did you replace the hoses?you might have a small pinhole leak. or the clamps might be loose...lose the pinch type ones and go with the kind that tighten with a screw driver.  

all hose clamps are screw type, no fluid is seen anywhere which is the great mystery.  

I had a similar problem with my 97 wrangler 4.0 it turned out to be the seam in the Radiator itself as you know the stock radiator in the wrangler is crap. the core is metal while the top and bottom are plastic and they tend to leak at the seam while driving and under extra pressure like when you accelerate but at idle or engine off/parked it does not leak.leave a puddle,nothing.This is somewhat of a common problem Thing is if the leak is at the bottom radiator seam you wont see it due to the fan shroud is covering it so you have to crawl under there and feel around the bottom for anywhere that is wet right after some hard driving also look for light steam or anti freeze smell. I replaced my radiator with an aftermarket all metal one  

my 2001 tj leaks from the upper radiator hose at the the clamp. this happens every time the weather changes hot/cold, wet/dry. i ve replaced the hose and clamp already but it still does it. i live in the deserts of ca. and the weather is extreme.  it only lesks a little bit but has a tendancy to accumulte at the bottom of the fan shroud so at cold start up it blows out and can be unnoticable if your not watching for it.
the coolant will leave residue stains but are really faint  

Pull your spark plugs and take a look at them. This can be a good indicator that you are leaking it into the cylinder and burning it. Pull all of them, not just one, cuz it would prob be leaking into just 1 or 2 cylinders.