squeaking belt on 6.4

grider · #1 (**permalink**) 01-12-2009, 10:09 AM

hello everyone,
i have an ongoing problem with my belt on a 2008 F350 6.4 liter diesel.
when the engine is running there is an aweful squeaking from the belt. someone suggested to spray some belt dressing on the belt to rule out any pulley bearings.
when you spray the belt dressing on the back side of the belt ( the smooth side) the sound goes away, but only for couple hours then comes back.
the dealer has changed the idler pulleys and the belt at least 3 times. since im out of warranty now i have replaced the them aswell only to last couple thousand kilometers then its back.
when seems odd to me is if you look at the back (the smooth side)of the squeaking belt it has a metalic shine to it, the only thing that the smooth side of the belt runs on is the two idler pulleys and the tensioner....
does anyone have any suggestions or has seem this before?
im just at a loss, truck sounds soooooo bad

thanks for any help

jmcbrid · #2 (**permalink**) 01-12-2009, 11:20 AM

I had/have the same problem - seems many do. I had mine to the dealer last year and first had the idler pulley replaced. That did not solve the problem until they replaced the belt. That fixed it until a couple weeks ago (almost a year later) when it started again when the temp gets into the low 30s - the difference now is that it is not very loud and only lasts about a minute or so. Last year prior to taking it to the dealer I did the following --

- Putting water on the belt immediately stops the noise, but doesn't last
- Belt dressing made mine squeal worse
- I even put sand paper against the belt while running - thinking if I roughed it up it would stop. Nothing worked until the belt change, but even that was not an actual fix.

There is a dealer broadcast (maybe a TSB) regarding this that basically states no known fix and to the dealer - do not attempt to fix.

grider · #3 (**permalink**) 01-12-2009, 11:27 AM

the last think that i did to mine was a new belt that stopped all and any noise, but it only lasted about 3 or 4 thousand kilometers, now the squeaking is starting again, not too loud yet.
i did the same thing you did, thinking roughing up the back side with some steel wool would help but it didnt,
it gets expensive to keep putting new belts on every couple thousand kilometers

DesertRider · #4 (**permalink**) 01-13-2009, 10:52 AM

I have a similar problem. My belt squeals once in a while when I start the truck, but only for a minute or so. But the worse thing is when it's hot, it squeals much more. Once when I was climbing a grade with my trailer the engine started to heat up. I've never seen the temp gauge budge before this. I turned off the A/C and the temp went to normal. When I reached the summit I turned the A/C back on. The belt squealed constantly and sounded like it was going to break. It didn't appear like the A/C was working, but I didn't leave it on very long. When I turned the A/C off, the noise stopped. I parked in a campsite and over an hour later I still could not turn on the A/C without the noise. I thought the A/C pump was frozen. The next day, everything worked OK, but I still hear the squealing noise occasionally, but it doesn't last long.
I'm taking the truck in for the radiator TSB next week, and I'll see what the dealer will do about the belt or A/C pump

CT-FREESKIER · #5 (**permalink**) 01-29-2009, 06:51 PM

i have a problem on my 08 f250 6.4 (still new with 2000 mi), however i am not sure if it is directly related to the belt or idler pulleys. when applying throttle, even just for a second or two, then let off, there is a awkward muffled rubbing sort of sound that is not constant; after immediately letting off the throttle the sound occurs in intervals that decrease with the rpms. Does anyone know what could be the source of the sound or has anyone experienced it before?

jiggy · #6 (**permalink**) 01-30-2009, 08:02 PM

hey ct-freeskier,
have you tried honking your horn 6 times and doing the rain dance? It worked for me.

rebelyell618 · #7 (**permalink**) 01-30-2009, 09:29 PM

i believe goodyear has a gatorback belt for your truck, maybe that will get the squeak out of it. 20-30 bucks for the belt.

Greyman · #8 (**permalink**) 02-03-2009, 09:36 PM

Just had my idler pulley replaced to combat the squeaking, dealer said truck was done. When they pulled the truck around it was still squeaking. Driver went and got the service writer and he said that he could hear it all the way back at his desk. I told him to call me when they decide what the next step is. Maybe another pulley and a new belt? Do you think it's just the belt or maybe both? Thanks in advance.

rmosso1 · #9 (**permalink**) 02-04-2009, 08:16 AM

Much like a guitar. I would check the tension first. Too little or too much should make a noise.

caprang · #10 (**permalink**) 02-04-2009, 11:43 AM

Courtesy of Maxium4x4 from another post

TSB
07-23-9 6.4L DIESEL - COLD WEATHER BELT CHIRP

Publication Date: November 9, 2007

Figure 1 - Article 07-23-9

PART NUMBER PART NAME
7C3Z-8678-B Kit - Idler Pull

WARRANTY STATUS:
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.

OPERATION DESCRIPTION TIME
072309A 2008 F-Super Duty 6.4L: Replace The Idler Pulley, Includes time For Upper Fan Shroud (This Labor Operation Is All Inclusive, Additional Labor Operations May Not Be Used) 1.7 Hrs.

DEALER CODING
BASIC PART NO. CONDITION CODE
8678 42

FORD 2008 F-Super Duty

ISSUE:
Some 2008 F-Super Duty vehicles equipped with a 6.4L diesel may experience a belt chirp when initially started following a cold soak.

ACTION:
Replace the idler pulley following Workshop Manual, Section 303-05. (Figure 1)

Greyman · #11 (**permalink**) 02-04-2009, 09:29 PM

That's the TSB they just did on my truck, calling them tomorrow and asking for another pulley and a new belt. Hopefully this will end the dying bird under my hood.

grider · #12 (**permalink**) 02-04-2009, 09:43 PM

my truck is out of warranty now so i bought both idlers and changed them out, the squeaking was gone, 2 days later it started again and got progressively worse.
then i bought another new belt, put it on and the noise was completely gone. that lasted couple thousand KM now its starting to come back again.....
it squeaks when you start the truck, it squeaks after the truck has been running for many hours, the other day after a 1600km trip continous driving the squeaking was gone.next morning its back and never goes away....... how do i know if the tensioner has too much or too little tension?