My 98 has intermittent issues last summer with belching coolant out of the overflow. I opened the purge, carried distilled water for a week, and eventually the air worked out of the system.
I had my water pump replaced and there was an air pocket hiding somewhere. The overflow issue was intermittent, and didn't manifest immediately afterward.
Try running the purge open for a few good heat cycles.
__________________
16 Focus ST
14 BRZ
00 Ducati ST2
|