I have 01 S80 that quit running , found power steering pump pulley gone and serpentine belt shredded and wrapped around crank . After removing and replacing pulley and belt engine won't start, only backfires. Any suggestions would be appreciated. Thanks

 

Ir probably jumped tomorrow ama damaged the valves

 

Thank you for the advice , is there a way to confirm this and is it a major repair worth the effort or better just to replace the engine ?