1999 JAGUAR XK8 Engine And Engine Coolingcooling System Problems

1999 XK8 CONVERTIBLE WITH @37000 MILES. I LEASE THIS VEHICLE AND KEEP IT IMPECCABLY MAINTAINED AT THE JAGUAR SERVICE DEPT. IN THE PAST YEAR ONCE WHILE ON THE FREEWAY THE ENGINE STOPPED/STALLED AT HIGH SPEED AND ENGINE LIGHTS WENT ON. THIS OCCURRED ABOUT 3 TIMES. I NOTIFIED OUR JAGUAR SERVICE PERSON WHO CHECKED OUT THE CAR AT NEXT SERVICE AND DID NOT HAPPEN AGAIN. TWO WEEKS AGO, THE ENGINE LIGHT WENT ON BECAUSE IT LOOKED LIKE THE CAR WAS OVERHEATING: FAN AND THERMOSTAT WERE REPLACED. ON SUNDAY, JULY 25, 2004 AFTER DRIVING 7 MILES TO UNIVERSAL STUDIOS ETC. CAME HOME AND AN HOUR LATER ATTEMPTED TO START THE CAR AND IT SOUNDED AT FIRST LIKE IT WAS TRYING TO TURN OVER AND SIMPLY MADE LOUD ALMOST FLOODING TYPE SOUND AND DIED. I HAVE NOW LEARNED THAT THE TIMING CHAIN WITHIN THE ENGINE COMPLETELY SNAPPED AND WILL NEED TO REPLACE THE...