Replace alternator pulley when replacing idler pulley?/Examining Belt Tensioner

The Idler pulley must have seized (?) and broken last night as it is no longer present and fell off behind the car. Got the car home and did some investigation to see what could have caused it and all the other pulleys seem fine to me:

-Alternator Pulley spins freely counter-clockwise, doesn't spin clockwise with screwdriver in alternator fan blades

-Power Steering Pulley spins freely with little resistance

-Tensioner pulley spins freely with little resistance

-AC Compressor Pulley Spins freely with little resistance

-Idler Pulley is no longer present

-Crankshaft pulley does not spin at all. I assume it will only spin when the engine is turning?

So I am looking at replacing the Idler Pulley. Do I need any special tools for this? It seems like the bolt that held it on has a strange recessed star head. Also I've heard the Alternator Pulley is something to watch to go on ALH cars and mine is approaching 170,000 miles. Should I replace it while i'm in there or give it time? $70 is sort of pricey for the alt pulley plus the tools unless I need them anyways. Does the Idler Pulley need to be removed to replace the Alt Pulley?

Any ideas on why the Idler Pulley would have exploded? Should I replace the Alternator Pulley now along with the Idler Pulley even though it seems to be ok as above? Would this have effect the belt tensioner, and is there anyway to check to be sure it is ok?

thanks!
-Anthony

It sounds like you have checked all the pulleys properly - must have been just the idler pulley decided to go.

Nothing special about replacing the idler - not sure what bolt you will need however as mine was still intact when I changed mine.

Myself, I would leave the alternator pulley alone for now since it tested out OK.

Replace the idler and put it all back together - then just look for any unusual movement with the belt & tensioner when you get it running.

Just my opinion as I just got done replacing just about everything in the serpentine belt path chasing a noise that turned out to be my alternator itself.

I recently replaced the alternator pulley after it sheared off the post while cruising at 65 mph. It was a bit of work, but the how too does a good job at telling you what needs to be done. You have to remove the AC compressor to get to the alternator.

When I removed my tensioner I cleaned it off pretty good and accessed its condition. I felt that it was in working order and put it right back on. After I had everything back in I was not 100% confident that the pulley failed because it commonly fails... But, I didn't know what to do to make sure that I remedied the problem.

I guess if I were in your shoes I would not replace the alternator pulley right now... It is bound to come off at some point. It isn't a big deal to replace and you don't HAVE to spend the bones right now... Good luck.

Carter

Thanks for your opinions and reassurance. Simple 6mm Hex on the Idler Pulley bolt to get it out and now just waiting for a new one from idparts. I'll see how it all checks out.