Timing Gears

Many general motors engines for YEARS have had a plastic tooth gear/sprocket mounted on the end of the camshaft, supposedly to make the engine run quieter. Regardless of your care and feeding of the engine, the teeth on this plastic gear/sprocket WILL wear out somewhere between 80,000 & 150,000 miles depending on how you treat your engine. When the teeth give out, it's like a timing belt breaking, and you can suffer internal damage from bent push-rods to bent valves.

Can anyone tell me if the 3100 engine in a 1998 Grand Prix has such a plastic gear, or is it fully steel?

Also, the owner's manual says nothing about checking/changing this gear/sprocket at any mileage. If it IS plastic, when should I have it changed to be on the safe side?

Regards, Gary in Sandy Eggo