serpentine belt tensioner replacement

Hello,

Here is a guide that will walk you through the steps and diagrams below to show you what it will be like for your car.

https://www.2carpros.com/articles/serpentine-belt-tensioner-replacement

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

how do i replace a serpintine belt tensioner on a 1990 ls400

The idler pulley is at the top right of the engine (if you are looking at it from the front of the car). Using either a long breaker bar on the belt tensioner pulley bolt, take the pressure off the serpentine belt - this is the belt that drives your alternator, water pump, power steering and fan, etc. Don't horse anything - you should not have to push too hard to know if you are taking the tension off the belt! Once you do that, slip the belt off the tensioner pulley and slowly let the pressure off the belt tensioner pulley. Next remove the belt off the idler pulley and using correct sized socket with the breaker bar or a hefty wrench, remove the idler pulley bolt. If the idler pulley is really shot to bits, it may come off in pieces; if not, there should be one center bolt and a largish washer. Don't lose the washer or bolt since your new part does not come with those (mine didn't!). Replace everything in the same order.

I have done all you have mentioned,and I still can't get it off. Please look at the photos I attached and see if we are on the same page.
Image #90 is the tensioner on the car, # 91 is the new one.

can you take some more pics? get a strater on shot of alternator area side of tensioner. from a lower position.