6.4l Serpentine belt chirp noise fix

WANTED said:

Would it be a constant squealing if it was when the motor is hot, or would it periodically come and go? The only other condition under which it happens is when the truck is under acceleration when it does occur. If I increase acceleration for a bit, I can get it to go away. I have no reference for what a needle bearing failure sounds like. If you have a link to a youtube recording somewhere, I could give you a better comparison to mine.




I'll give the garden hose method a try. I did check the pulleys when the belt was off and found nothing the seemed out of the ordinary, nor found any binding. I may just say the hell with it and replace all the pulleys. The belts fit perfectly over everything and exhibit not odd movement when the truck is running at idle. The noise got better when I replace the belts and tensioners. The TSB may in fact be the culprit and what I perceived to be within the norm of tolerance may in fact be off.



I'm curious as to what they revised to. Is it kevlar or something else? Any pictures of the differences?



This one is definitely one of my trickier squeals to diagnose. Pinpointing it has been a pain in my ass. This noise is less troubling and more annoying if anything.

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The way your describing it I would check into the revised idler pulley and think about that ford belt. I know when they first revised it the belt was very slippery new and was called a improved coating for noise. If I remember right though the newest one has rough backside to it like the belts on the newest ford cars, I will see if parts has one in stock to take a picture tomorrow.
The TSB was only for specific build dates though.

FORD: 2008-2009 F-Super Duty


This article supersedes TSB 07-23-9 to update model year, Service Procedure and Part List.

ISSUE:
Some 2008-2009 F-Super Duty vehicles equipped with a 6.4L diesel may exhibit a front end accessory drive (FEAD) belt chirp when initially started following a cold soak.

ACTION:
Follow the Service Procedure steps to correct the condition.

SERVICE PROCEDURE

On 2008 model year vehicles built on or before 11/9/2007 and equipped with single alternator, replace the idler pulley following Workshop Manual Section 303-05. (Figure 1)


Figure 1 - Article 09-9-8


On 2008 model year vehicles built on or before 11/9/2007 and equipped with dual alternator, replace the idler pulley following Workshop Manual Section 303-05. (Figure 1)
On 2008 and 2009 model year vehicles equipped with single alternator, replace the main FEAD drive belt with a new service belt that has an improved noise resistant rubber compound.

PART NUMBER PART NAME
7C3Z-8678-B Idler Pulley
AC3Z-8620-B Belt

So I checked we had both versions of the belt and they look the same nothing special except the extra slippery backing. Oh and the new belt is only $37 now! Also in case you haven't heard Ford Motorcraft parts now come with a 24 month UNLIMITED MILES warranty. Here is the pics of the belts. Look the same to me...

makuloco2000 said:

here is a perfect example, I love how this guy narrates his videos.

http://www.youtube.com/watch?v=_E8qVO8Q934

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Yeah, mine sounds nothing like that. I'm pretty sure the TSB is at play too.
Thanks for your help.

Yep hope you find your chirp, and get rid of it for good!

I had my idler pulley replaced 3 years ago under the aforementioned TSB by my Ford dealer. Since that time, the chirp got less frequent, but that could be because I lived in FL. When I took a trip to the north, after sitting overnight, the chirp returned.

Yeah I am sure there were quite a few out there that actually need the revised idler. Just never seen any it fixed.

So I switched to the revised belt, and replaced both pulleys. Zero change. It's coming from the general area of the fan and am starting to wonder if this could possibly be my water pump or something else associated. You don't by chance have good how-to on replacing the water pump, do you?

Take the belt off and start it and see if it's still there. If not then you know it's with the belt or something belt driven. If it is there then you'll need to dig deeper.

Dogman said:

Take the belt off and start it and see if it's still there. If not then you know it's with the belt or something belt driven. If it is there then you'll need to dig deeper.

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Yes I agree as I stated earlier, its the sure fire for where to head next

It's a pain in the butt looking for thing like that. I have a coolant smell I can not find. I lose maybe less then a cup every 6 months and I can not find were the smell is coming from. I done psi test, no drop test the cap, it fine. Looked at all the hoses nothing.