We got an Olds 2004 Alero used. We constantly hear grinding- rattling from motor

This would require a hands-on inspection. It's hard to tell you exactly what's going on with your engine without seeing or hearing it. If it's a rod and requires a rebuild you may want to look into sourcing a used engine from the junkyard. Rebuilding it would not be cost effective on that old of a car. Alex

Don't see engine size posted - as usual - 'IF' 4 cylinder - have timing chain and components replaced - this includes the water pump..