The timing chain in my 2002 Oldsmobile Alero broke last fall. I had 72,000 miles on my car at the time. It caused significant damage to the cylinder head and end up costing me a lot of money mostly in labor costs to get the car fixed. I really hope it doesn't happen again anytime soon but does anyone know approximately how often or after how many miles the timing chain should be replaced. BTW, there's nothing in my owner's manual about replacing the timing chain.