Have a 99 expy 5.4 liter. At the number 3 coil pack collant is coming up when you idle the engine up. The coil pack is on and i increased the rpm and coolant flowed vertical from roughly the back right side of the coil pack. What could it be? No white smoke from exhaust pipe, antifreeze is fine, and engine oil level is good with no bubbles. Ford dealer said it was a cracked head