All I know about these and timing chain is they don't like low oil levels. These engine prefer overfill than running low. The oiler at the top of the chain system will start to sludge up and eventually clog if engine is run low on old oil. So if yours runs good and doesn't lose too much oil between oil changes, you should be good for a while yet. But understand that with 100,000miles you should check the oil a bit more regularly.
---------- Post added at 05:41 PM ---------- Previous post was at 05:20 PM ----------
Just dug this up on tensioner concerns. Old tensionners weren't bad they just changed the design to eliminate "O" ring.
---------- Post added at 05:44 PM ---------- Previous post was at 05:41 PM ----------
Here's a funny little paragraph added at the end of that Bulletin.
GM bulletins are intended for use by professional technicians, NOT a
""do-it-yourselfer"". They are written to inform these technicians of
conditions that may occur on some vehicles, or to provide
information that could assist in the proper service of a vehicle.
Properly trained technicians have the equipment, tools, safety
instructions, and know-how to do a job properly and safely. If a
condition is described, DO NOT assume that the bulletin applies to
your vehicle, or that your vehicle will have that condition. See your
GM dealer for information on whether your vehicle may benefit from