10 days ago my 03 Envoy leaked about a cup of water under the overflow reservoir, above the passenger tire after driving a few blocks. the next day at leaked about 3 cups of water after a 20 minute drive. It was cooler out, not a hot day and I can’t pinpoint where it’s coming from but it’s not the radiator. it hasn’t leaked since any idea a what happened? The coolant level is a little low but above the fill line.
The first thing to try is replace the overflow reservoir/surge tank cap.
https://www.rockauto.com/en/moreinfo.php?pk=295427&cc=1415269&jsn=391&jsn=391
If this cap can no longer hold the proper cooling system pressure, it’ll allow coolant to be pushed out of system.
Tester
Another idea, if 4 cups leaked out and the level is still above the fill line, maybe it was just over-filled. My Corolla won’t hold an extra quart of coolant without complaining and spitting some out in protest. Alternately, another guess might be that what you are seeing isn’t coolant, but normal condensation draining from the AC system. Give it the smell test. Coolant has a sweet odor.