2010 Squeaking on Acceleration/Idling With Load

SprinterGuy100

New member
2010 170" WB HR Passenger W/Rear AC, 138K miles

As the title states, sounds as though something on the accessory drives is amiss. At idle, with no load (ie no AC or obvious electrical draws on) it idles normal and quiet. If I turn on the AC, there is a slight squeaking noise, coming from the drivers side of the accessory drive area. It sounds more bearing like then it does belt squealing-like, but its faint enough its hard to tell.

For the past two weeks we have noticed a squealing noise while driving, though it is very faint. You can't hear it rolling down the windows while driving due to wind noise, but you can hear it coming from engine compartment. It is much more prominent while accelerating, and goes away when letting off the throttle (even if RPM's stay the same when its coasting in gear). So I went and bought a serpentine belt kit. With both belts off, I spun each pulley/idler and nothing felt wrong to me. So I installed the new belt tensioner and belt, and the sound is still there.

Now, I will admit, I didnt replace the idler bearing/pulleys. Why? Because I ran out of time last night (this is my wifes DD) and because I was unsure if I needed to remove the fan, or fan pulley, or the whole fan/fan bearing mount to get to the top idler pulley since its right behind the fan's pulley. Any advice there would be great. I did notice that the new pulley is smooth, while the old one has groves worn into it from the ribbing on the belt. Now, when I spun this idler pulley, it felt fine to me.

It almost sounds like the sound is coming from the power steering pulley area as best as I can tell. Power steering fluid level is fine, and appears clean. The noise is much more prominent when the AC is on, which had me thinking perhaps its an AC clutch or bearing starting to go.

Besides the obvious that I should throw the two tensioners on, any other problem areas to look at? Bold for the parts I think are key to tracking down the issue. We leave Thursday evening on a 2600 mile drive so I'd rather not chuck a belt due to something really being wrong here.
 
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Deleted member 50714

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Replace the pulleys. Ensure proper belt tension
 

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