You obviously have a serious coolant leak issue you need to deal with before you worry about the overflow.
Start the car and just let it sit there and run until you see where the coolant is coming from.
If the exhaust smoke is white.........
__________________
1976 Mazda Cosmo RX-5
1976 Mazda Cosmo RX-5
2003 Toyota Tundra TRD
2015 Toyota 4Runner SR5
|