Coolant Light Blinking

[Seadweller]

Greetings,

About 6 weeks ago, I had my Indy do a coolant change/flush, along with a bunch of other standard service items, on my recently acquired '98. Drove the car home and put it away with nary an issue. Took it out a week later to find the coolant light flashing. I called my Indy, and he said bring it right in. The coolant level was evidently perfect, and they pressure tested the system and found everything to be 100%. I drove it for the rest of the day without an issue.

Took it out the next weekend, and drove it all day without issue. Fast forward to yesterday, I took it out to stretch its legs on a couple of errands, to find the coolant light was blinking again. Arrived at my first stop, popped the lid, and opened the coolant reservoir and it was like slowing removing the lid off a bottle of tonic water. Checked the level and it was fine, replaced the cap, started the car, and the light was no longer blinking.

Any idea what might be causing this intermittent issue? The coolant light never came on until the coolant change/flush.

Thanks!