Had the same problem, topped off the coolant reservoir......problem solved! But wait, why was the coolant low?.......the missing coolant was leaking into the transmission and vice-versa. Several 1k miles later the transmission failed. Had it rebuilt $$$$$. Now I need the rear u-joint replaced. ..........I think for your 2005, it is just a matter of time. If everything still seems to work fine, I would get rid of it as soon as possible.