On August 26, 2004, while returning from a short (less than 1 mile) trip from the store, the 928's Achilles heel struck my 928. I had backed out of my parking spot and just put the car into drive when an awful metal knocking noise came from under the hood. When the car stalled and the dashboard lit up like a Christmas tree, I instinctively knew that my 928 had suffered a slipped or snapped timing belt. I got out of the car, popped the hood and pulled off the air intake tubes to look inside the timing belt covers. The passenger side still showed a belt on a cam gear, but there was nothing but a shiny cam gear on the driver's side. Coolant began leaking all over the ground.
I pushed the car into a safe location and had it flat-bedded home the next day. This web page chronicles my journey to repair a 928 following its timing belt failure. Hopefully it will encourage other owners to pay closer attention to their timing belts. My own timing belt was about 15,000 miles and 15 months old. It had been retensioned 2,000 miles after installation. I had recently retensioned it again after receiving a warning light. Timing belts are supposed to last 60,000 miles or 4 years, but most people recommend changing them after 45,000 miles.
Thinking back the the possible warning signs that should have alerted me, I remember that I received two belt tension warnings in the 6 months prior to the failure. Each time I used the Kempf aftermarket belt tension tool to check the tension. Both times the tension was too loose, so I re-tensioned the belt back to the proper tightness. I didn't notice any burning smells, but I did get a low coolant warning a few weeks earlier. As I eventually found out, one of the bolts that seals in the engine's coolant was bent and there were many signs that the belt had actually been too tight.