Quote Originally Posted by brooky View Post
It happened when engine is hot after some time driving. No air con just seems to be random. could it be the fan or alternator clutch engaging?
The fan load would be constant at speed. I dont know of an alternator with a clutch - simply have not seen one, but if the a/c clutch comes on, the sudden engagement is typically handled as belt slip for an instant - its not that savage an action. How many of these events have happened - two? It looks like a casting/housing failure to me, but hard to understand why the bolt is shearing as well.