I'm referring to the bolts that mount the bracket to the motor and not the tensioner it's self.. does anyone know what size the bolts are?

M-10 x 1.25 bolts the tensioner assembly to the engine.  If your dealing with stripped threads , be aware that the section of block it bolts to is removable and replaceable . Much safer than tapping a stripped hole.    If you are referring to the replaceable section of block ... bolts are M-8 x 1.25

Edited August 19, 20178 yr by montana tom

what year and engine, and which tensioner bolts?

 

Timing belt? Alt belt? A/C belt?