Thought I'd post a pic; although I imagine it's pretty obvious if you see it - one of those "what the heck!!" moments.
I started hearing a noise and thought - "that sounds like a loose belt". So I checked and the tension was fine. I kept driving it, and decided it it was more of a squeak than a squeal. Finally took the belt off to inspect it - I did notice that it wasn't riding in the center of the tensioner pulley. Once I got it off it was obvious. After unbolting the shock there was tons of play in the tensioner bearing and with a mirror I could see the balls in the bearing - that can't be right. In the picture you can see that the tensioner bolt is offset in the tensioner.
The tensioner bolt is bigger than a 10mm allen, I read in another another thread that it is 12mm - can anyone confirm that for a 603.971?
And does anyone recall if it is a right or left hand thread??
I got the tensioner pulley off (6mm allen) and it's fine. Turned everything else by hand and they seemed smooth, no noticeable noise, and no play. Shock and all the other bits and pieces alook fine.
EPC says I have either the second or third version in this diagram
Looks like it will be easier to replace the tensioner if the fan clutch comes off (my repair manual says to take it off) and I've been thinking about replacing the fan clutch and the water pump so i think those will be on the list too.
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And of course, after seeing the state of the tensioner - I probably shouldn't have been driving it. Hope it is just the tensioner.