When my belt was having issues (pulley alignment) I never saw any KR readings on the ScanMaster. Instead, I thought I heard knock at WOT with the windows down but none of the gauges showed anything.
My belt ended up squeaking badly; I found the alignment issue and fixed it, no problems since.
Had a 635 on it. Pretty old circa 2006 or so, a bit glossy. New one is on the way from rockauto. Tensioner feels OK (smooth spring action) but maybe it's weak? Might also try a 630 belt.
I can hear something slapping on hard accel. Getting little bits of KR (1.1 degree, 0.7 degree) that seem to be related to the sound. Car is detuned to avoid KR and plugs agree, very clean porcelains.
Had a 635 on it. Pretty old circa 2006 or so, a bit glossy. New one is on the way from rockauto. Tensioner feels OK (smooth spring action) but maybe it's weak? Might also try a 630 belt.