Hey Gents,

I heard my wife drive in today and man that AC was making the serpentine howl! I took a look at the idler pulley and it is just bouncing around. I figure those bounces are causing the belt to chirp with increased torque load on the serpentine with AC in run. My plan is to replace the belt tensioner and belt and check free movement of all the auxiliaries. Just wondering if anybody ran into something like this? How do tensioners fail when they are a spring?

With respect, I'd suggest you check to OAD before you get too carried away with buying other parts.

Replace alternator pulley or entire alternator. Bad alternator decoupler pulley causes that bounce and it can be worse with AC on.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

replace all the idlers and the tensioner if the belt is bouncing all that stuff is over stressed

That bad boy is expensive. I tried replacing the alternator pulley at 93K (Currently at 130K) and I just gave up. Getting the pulley off was a lot of work. The alternator was covered under warranty around 105K. Sadly the warranty is gone. I still have the pulley and will replace idler, belt, and tensioner as well.

I have a electric impact wrench from harbor freight, http://www.harborfreight.com/12-in-elec ... 68099.html, takes off and on the OAD in about 30 secs

Is OAD a fancy name for the alternator pulley?

It is indeed. The fancy name is Overrunning Alternator De-coupler.
If you do need one, it's important to get a real one that's not a cheap knock off as in a friction clutch. There's a bit been written on here recently about that and the recent updates to designs by Litens.