Hi!

Recently I changed timing belt and I had to remove the idler pulley that tensions the serpentine belt.

 

Does anyone know what is the torque value for the bolt that sits on the idler pulley of the serpentine belt, (see picture)?

Manufacturer's book does not say anything about that.

 

 

It's high tensile, is it M8 or M10 metric fine?

It is M10 ( I used wretch size 16mm).

I think this will help you

https://workshop-manuals.com/volkswagen/polo-mk4/engine/4-cylinder_injection_engine/enginecrankshaft_group_pistons/dismantling_and_assembling_engine/part_i_assembly_overview_belt_drive/

https://images.app.goo.gl/Hjsd6UJar4R1Pncm6

 

50 Nm.