[Perfectlap]

Pedro is spot on. After the coolant was flushed last year I noticed there was an air bubble in there becase I was getting a false half empty measure on the indicator. Wasn't running hot and neither did the dashboard light start blinking. Not sure where the airbubble went but the indicator rose back to normal level. Well on second thought I guess I do know where the air bubble went, it made its own exit.

So yeah, don't flush and if you do get ready to spend $300 on a new unit. Luckily I was at home when I noticed all the coolant was gone.