fan belt popped off!

[david beer]

Coming home from TMS this afternnon, my alternator belt "fell off". The red light came on followed in seconds by the temp rising. Luckily it was still there and for once i had the wheel brace in the boot and managed to put it back on. Anybody know why? Its a year old, good condition. No wobbly bits, ie water pump etc, the spring loaded adjuster is strong.

[greenv8s]

Coming home from TMS this afternnon, my alternator belt "fell off". The red light came on followed in seconds by the temp rising. Luckily it was still there and for once i had the wheel brace in the boot and managed to put it back on. Anybody know why? Its a year old, good condition. No wobbly bits, ie water pump etc, the spring loaded adjuster is strong.

Assume it's a serpentine belt since you mention a tensioner? Assume the tensioner is actually keeping the belt tight and the belt isn't damaged, the favorite reason for these to come off is because of a pully out of line. If it happens again, it would be worth checking that none of the pulleys have any play in, and have a careful look over the belt for damage. You were absolutely right to stop, with no water circulation you can get hotspots in the heads extremely quickly if you are driving hard.