Engine Mechanical problem
2000 GMC Jimmy 6 cyl Four Wheel Drive Automatic 87,500 miles
My belt underneath has no cracks, chunking, or grove wear, however on top of the belt on the smooth side, there are a few spots all along the same line where there are some groves here and there in the belt. What causes that, and what should I do about it? Otherwise the belt looks to be in great condition. The grove spots have not worn thru the belt, they are near the surface in in only a few small spots. I've heard stories about Jimmies shredding serpentine belts, so I'm a bit concerned.
There may have been at some time some foreign material caught under the belt on an idler pulley, if the belt looks ok don't bother, normal rule of thumb is 10 cracks in the ribs per inch length average before the belt should be replaced, if at all in doubt replace the belt and check idler & tensioner for problems.