I've been having the common problem of the overflow dumping coolant after shutdown. I'm trying to diagnos whether it's the coolant seals or just a leak somewhere. A tiny puff of white smoke on startup. Can't smell coolant over the stink of unburned fuel. Changed the filler neck cap. Haven't changed the AST cap yet (aluminum aftermarket less than 2 years old). Temp on the car doesn't budge. PFC reads 87 degrees around town. Put a funnel in the filler neck the other night, started the car up, and let the coolant level rise up into the funnel. Once the car approached operating temp a single bubble (about 1 inch in diameter) popped to the surface. After that, they would appear about every 10 seconds. So, after searching the forum, I see people describing the bubbling as "constant," or a "stream of bubbles." Are these bubbles I'm seeing different from would typically be seen with bad seals? Also, when the fans kicked on, the coolant in the funnel became VERY cloudy. It looked like smoke pouring into the coolant. No idea what that was. Could it be exhaust???