Just had the engine die on my 156. Starter making a 'not engaging' sound. Feared the worst - cambelt broken, but breadown guy said it's lost a tooth from the belt. Will this be terminal or is it possible a new belt might be ok?
it would make the cam slip round 1 tooth when it tries to engage where the missing one is and will slip past to the next one - maybe as much as 10 to 20o of arc difference. Cant be good but probably threw the cam out enough to cause compression leak due to valves being slightly open when they should be shut.
You may be lucky and not have piston to valve contact
My 156 jumped 3 teeth (belt did not snap) when waterpump failed at 16K miles, the mech said I was lucky it did no damage...One new waterpump and cambelt and all was well....so you might be lucky...best of luck