just some follow up...spent about a day in my very helpful friends garage, and changed a lot of parts, including the timing belt,,turns out I have the hydraulic tensioner...wasn't as bad as I thought, just take your time..only thing I did different, book/websites suggest allowing tensioner open up, then insert the white plastic spacer, I found it near impossible to do this with tensioner in place, so mounted tensioner with spacer already in, with a little maneuvering, went right in...did the water pump while in there, figured might just as well, was original, wish I had miniature hands for that repair, not much room to work...where can I buy that special fitting to move tensioner arm when installing serpentine belt?? a pry bar will work, but makes job much harder than it needs to be

With some advice from others on this board, I did mine a couple of weekends ago. The old FCP Groton site listed the hydraulic tensioner cut-off as being engine #1266127. I brought my engine number to the dealer to confirm when buying the belt. The engine number can be found on the timing cover under a bar code.

A more reliable way is to just remove the timing cover and look. Slide the coolant tank up and out of the way (disconnect the level sensor on the bottom) and remove the timing cover bolt with a 12mm socket. You'll be able to see the tensioner from there.

Good detailed instructions can be found at Bay13: http://volvospeed.com/maintenance.shtml

The instructions for mechanical tensioners are on that page as well, it just takes some digging.

Good luck.