Blue Temperature Light
 

Just bought a used 2000 Beetle. Love it! However, the blue temperature light comes on almost immediately when I start the car. It will go out. Come back on. Go out. Sometimes it will flash. The previous owner said it has been to garage previously for the dashboard light issue, and her mechanic said the idiot lights are sometimes buggy and will malfunction like that, and not to worry because everything is OK. I have no reason NOT to believe her, but just wondering if anyone can confirm that this is fairly common and not a concern. Thanks!