Replacing the cam belt and found the spacer washer missing oh and tons of oil.all cleaned out now and going to replace the crank seal as it's not in square and there's a hole in it looks like they use a screwdriver to punch it in( I paid a garage good money so they could screw this job up last time)
I need to know how thick the washer is I'm guessing it will sit flush inside the round hole of the tensioner bracket can someone confirm this?.

Would help to know the engine?

Ill answer for a 300tdi -

Current setup is not to use the spacer.

This is assuming the rimmed crank sprocket, and flat (no rim) idler.

Sorry yes 300tdi I have the mod kit have bin reading about and you are correct the washer is not needed.thanks for the help.