Engine Whine Noise finally diagnosed and resolved

[hiking_mike]

I was starting to panic. A few weeks ago, 2007 stock LMM started to give a high pitched whine noise. All videos I saw on the web listed several possibilities. I was praying not Turbo or boost, or EGR related. As my sound was just like many of the videos.

It was RPM related, regardless if engine was warm or cold.

 

I first looked at the Power Steering pump: Flushed fluid ( 125k miles )

I tried to listen to pin point where it was coming from, with out any luck.

I decided to remove the serpentine belt to see if it was front of the engine related.

After taking the belt off, I discovered the issue.

Lower Idler Pulley was seized up pretty bad.

 

FYI, I did not remove the inner fan shroud, just removed the upper bolt.

This gave me room to move tensioner and remove belt.

I got the bolt out of the idler pulley, but there was not enough room to get the bolt back on.

I used a file and filed a "notch" into the back of the plastic arm supporting the inner fan guard.

This gave me the 1/4 inch needed to get the new pulley and bolt back in.

 

Results: The engine was back to sounding "normal" again.

 

Just an FYI and I hope I can help someone out there.