I went to a 1/2 mile speed acceleration event last weekend and developed a coolant leak. The technician Kieth that I use at my dealership found that a plastic molded coolant passage under the supercharger failed. So in repairing that he also found that there was "take up" spring in the supercharger shaft had lost tension so he is replacing the whole nose shaft assembly on the supercharger. I had mentioned that there was a lot of clicking at idle from the supercharger (like the blades were banging a bit). He is, also, replacing the water pump with the newest version that is 2 piece as opposed to the older units that are 3 piece. The old pumps say FoMoCo and the new ones say Jaguar and made in Italy. I'll attach som pictures of the pumps and the top end broken down. I should get the Cat back tomorrow, driving an XF just doesn't make it for me.