I have replaced at least 10 timing belts in my life 90% on 240 volvos.

Something very unusual has happened this time. I noticed that the engine had a different sound, sort of grinding noise. It seemed originating from the power steering pump but I did not attach too much importance to it.

My wife left home with the car and it stopped at three street corners away.

My son and I towed it back home with a yellow cable. Unseen by police fortunately.

The timing belt did slide off the tensioner and cut two holes 1/2 x 2 inches in the plastic cover but was not broken. Only the edge of the teet were worn. This is a Volvo timing belt.

I wonder if the tensioner was not enligned properly or what ?

Has something like this happened to you ?