Hi Guys.. Our 2009 model Volvo recently threw a timing belt, 3 days after a vehicle service with 80,000km on clock. ( life span of timing belt per service manual 180,000km.)
Mechanic serviced the alternator belt (called drive belt in Australia), but did not change any pulleys.

The alternator belt shares crank shaft pulley with timing belt obviously, although the timing belt has light weight cover.

I believe the tensioner pulley on alternator belt has failed. The mechanic has either not checked the tension roller or replaced with wrong belt. ( unlikely the belt)
On third drive of vehicle after the engine timing belt shredded.

I believe through the service the adjustment to the tension has been wrong or alternator tensioner roller has failed . Belt has slipped and thrown/tangled on to timing belt, via the crank shaft pulley.

Engine is now stuffed, cheaper to buy new engine the fix bent valves and replace head.

Has any one seen this problem before??Any assistance greatly appreciated