a few months ago i saw a 2 inch drop in coolant with no hint where it went, no smell,no drip, tranny looks/works ok as normal.
i filled to the line and 2 weeks ago it was down an inch. i did nothing,still no hint.
took a 1000 mile trip and aok,zero problems, still 1 inch down. temp is as always just below 1/2 even idling in 90+ air

any ideas???

 

I had the same problem. Wound up being a small crack on the top tank of the radiator. The coolant evaporated as it was leaking. Once down below the crack it doesn't leak very much at all.

 

THAT, would be "good"news, thanks.

i see nothing so far

 

My 2008 H3 radiator cracked at the top too. Might be a common problem with these things.

 

i still find no clue, nothing visible. i think a leak would let the pressure drop and lead to overheating??
still down one inch after about 1100 miles.

later:::
i filled to just above the case split and ill watch it daily. idling i notice nothing,smell nothing.

 

Its wierd my coolant did that once too but only once. No smell, no hissing, no noticeable vapor, nothing in oil when I changed it. No clue what happened. Filled it up again and two years later might be down a bit but that has to be normal evap. No clue whatever happened. Maybe had a leak that got sealed somehow? No clue.