Any possible elaboration on that?
I think if you run a search on timing chain tensioner you will see. The older ones are plastic, and break easily. The problem with this whole deal is that its down into the engine and you can't see it unless you have the front of the engine taken apart, or you have some sort of special scope.
Another problem they found is that when it breaks, you really don't know, and then all of a sudden your timing chain starts acting up, not sure if this can damage the engine. There's alot of info out there on it, I believe it might be on the GTO website....you'll know when you see it, its a yellow piece of plastic, crappy design, that's why it was changed.