Hi gang, as some of you know my '98 540I is giving me "check engine" message. I've checked the oil level and it's fine. The engine temperature was fine after driving it around for 20 minutes so i didn't really check the coolant level until this morning. Well, the red plastic "stick" is about an inch above the rim of the tank. I believe that the diagram says that the "stick" should be the same height as the rim of the tank. Could this be my problem? Do I need to add coolant? (again, the temperature gauge says that the engine temperature is normal)