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Discussion Starter #1
Loud grinding noise randomly started a couple weeks ago. It doesn't do it all the time. Usually first thing in the morning or when i leave work. I tried to make a video but the sound is very low.

When the noise starts the engine cannot keep itself running, rpms start going crazy. if i give it some gas it will overcome it. but the noise is still present and the engine struggles when you let off the gas. Sometimes it will stop within a few mins or if i kill the truck and restart it it will go away. Engine has always started back up if this caused it to die.

Thanks for any help!
 

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CALI BOSS
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Hard to tell from the video. It could be a bad water pump bearing. It may even be the tensioner pulley or the idler pulley.

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It could be the fans clutch , if you haven't switched to electric fans. Check the fan blades for tightness. Other than that , DBNissan 's comments bear merit also.
 

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I'd take the belt off and run it for a few minutes and see if the noise went away. That will eliminate all the belt-driven stuff. If that stops the noise, then you go pulley by pulley looking for something loose or binding. The fact that it seems to be most apparent at specific RPM's makes me think it's a bearing that's gone bad in a belt driven item. Bearings will "wobble" at specific RPM's and as they continue to wear out, the RPM range where they act up will get broader.
If it's not a belt driven item, I'd focus on the clutch, release bearing and flywheel. But that noise wouldn't be coming from under the hood probably.
 

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OldGuy has a point. Another old school method to check if its a bad bearing in a pulley is to put a broom stick on the centre of the pulley while idling. You got to be careful, but the bad bearings in the pulley will be making a loud, odd noise. The sound will carry up the broomstick. If you put your ear on one end of the broomstick and go from pulley to pulley, you will discover one making a loud noise compared to the normal sound the others make. I know it sounds like it wouldn't work but it actually works quite well and it is free :)
I did it on my Chevy S10 and diagnosed a bad bearing in a tensioner pulley. It was an easy fix.
 

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Discussion Starter #6
I wasn't able to figure out what was wrong. i checked the pulleys and fan and water pump. what ever it was finally broke on me. The drive shaft made a jerk when it broke. Truck wanted to die and i limped it home. I had to keep the rpms really high for it not to die. when it idles it feels like the truck is shaking it self apart. Thanks for all of your recommendations will update when i figure it out.
 

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Didn't realize before that it's a manual transmission. Bad release bearing or "throw out" bearing (same thing, different names) or something wrong with the clutch itself. Drop the transmission and look at the clutch and flywheel.
 

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Discussion Starter #8
thanks. If this is the problem would the truck have same symptoms when in neutral or does it matter?
 

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Discussion Starter #9
Solved: It was the Varible Timing Valve Actuator that broke. Truck also needed a new o2 sensor and throttle body cleaning. Runs like it did in 06. Thanks for all the help!
 
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