e-450 engine rattle - serpentine belt

mini4mw said:
Ever since it was new, the RV would have a fast rattle in the engine compartment when accelerating between 1800-2400 RPM, mostly 2nd gear, 30-45MPH. Sometimes it would happen for a second or two, other times for several seconds. Seems since it has got colder it doesn't happen as often. It wouldn't happen throughout the entire RPM distance, but it would almost always be there, usually ~2100RPM. Let go of the throttle or when it shifts and the rattle goes away. After 12k miles I finally decided to start trying to figure out what it was. Engine runs fine, no power loss, no mis-fires. Its not bad gas as I've gone through plenty of tanks. I stuck a gopro off the radiator and captured the below.

https://youtu.be/Oa6cr2dFkPE

You can hear the rattle start at :15 and then watch the belt vibrate erratically until you don't even see it for a few seconds. Rattle slows down and belt goes back to normal.

What is the cause of this? Bad belt? Bad tensioner? Pulley out of alignment? Something else? I'd think worst case is premature belt failure, right?

thanks-
Click to expand...


Great idea on the video. I have been chasing the same issue myself on my 2018 29 MV Greyhawk. I was concerned that it might be an internal engine issue. I took it to a ford dealer, they had it 3 weeks and said it was "something in the engine" well duh. They said ford might not cover the tear down and repair since i change my own oil, so i took it back. I even bought a blue driver and it showed no internal fault codes. The research i did on this forum and other ford e450 sites indicated that it is likely the bearings in the idler pulley. Based on your video and the fix, I am relieved that it's not internal. I'll get it to another dealer and have them change the belt and the pulley. Thanks, good job!!
 
Been following this thread as I am on my 3rd Class C on the E-450 chassis and on the 2 previous units (both used) I immediately replaced the serpentine belt (preventive maintenance) and kept the old as a spare. I never heard any type of rattling on the 2004 or the 2013 units. I now have a 2019 Greyhawk 30x and no rattling to date (a little over 8k miles).
After reading about the original poster replacing the serpentine, I’m wondering if the act of “exercising” the tensioner to remove / replace the belt might have corrected the issue? If you think about it, if the tensioner doesn’t move correctly, it might not take up slack as rpm increases or at certain rpm ranges, etc. in order to replace the serpentine belt, you have to force the tensioner all the way “slack” to remove and replace the belt - maybe that’s the fix? If the OP did another video same as what was posted, I wonder if you’d see the belt slacking as much. Of course now that it’s a new belt, it wouldn’t be an apples to apple comparison - just a thought.
 
mini4mw said:
https://youtu.be/Oa6cr2dFkPE
You can hear the rattle start at :15 and then watch the belt vibrate erratically until you don't even see it for a few seconds. Rattle slows down and belt goes back to normal.
Click to expand...


In your video, is the vibrating section of the belt located between the power steering pump and alternator? If so, this is the longest unsupported section of the belt (no idler pulley).
.
 

Attachments

  • beltflutter.JPG
    beltflutter.JPG
    25.4 KB · Views: 13
  • Belt.JPG
    Belt.JPG
    19.4 KB · Views: 324
That is the correct location of the vibration. The longest run of the belt with no support/pulley tension. I showed a friend and said he had never seen a run that long without support. I'd est ~ 2'.

When I lined up the old and the new belt the width was exactly the same. The length was hard to tell due to the creases in the new belt and being unable to get it perfectly straight.

The old belt was a little easier to get off than putting the new belt on. From memory it felt as though the new belt was just as tight as the old one when it was on. The old belt was more supple, but it does have 3yrs on it. The new belt does have the creases in it from being packaged and was more stiff. I don't believe the new belt is any tighter on the pulleys than the old and the belt tensioner is not the issue.

If you look at the picks of the worn Motorcraft belt, you can see it has either worn unevenly or manufactured unevenly on the sides. There was no fraying, but in some places you see the inside poly threads and others you don't. This should make the belt unevenly weighted on the sides, possibly uneven tension between the sides of the belt and perhaps on the long run caused the vibration at certain speeds or engine vibrations at those RPMs. No physics degree to show why it would do it, but uneven makeup on the sides of the belt, which could cause the start of a wobble on a long span makes sense to me.

I think its just the belt. My unknown is that did it wear and the uneven manufacturing caused it to show up after a period of time (what I'm leaning to as a number of people seem to have this issue while doing research (forums for Forester, Thor and other RVs) or does the belt wear unevenly against the fan pulley (as shown in pic where the paint is gone on the inside of the pulley) and cause the belt to stretch/wear unevenly and just needs to be replaced more often. Results of belt replacement should tell us over time.

note: I bought the Continental belt b/c it had the 3yr warranty and it was in stock at a store close by. Someone mentioned using a Gatorback Goodyear belt, but I believe from searches these may now be the Continentals. The Gates and AC Delco appear to be the same, just sold under different names. Ratings from people/sites on Dayco vs Gates vs Continental were all about the same so I went with the cheaper, longer warranty, in stock and store that was closest that I usually go to for parts.
 
mini4mw said:
That is the correct location of the vibration. The longest run of the belt with no support/pulley tension. I showed a friend and said he had never seen a run that long without support. I'd est ~ 2'.
Click to expand...


I did a bit of investigation, and it looks like some earlier V10 motors had a second idler pulley mounted so that this long section of belt was supported.

And on newer motors the mounting boss may still be there.


Interesting...


.
 

Attachments

  • 2000 diagram.JPG
    2000 diagram.JPG
    96 KB · Views: 51
  • pulley mount.JPG
    pulley mount.JPG
    28 KB · Views: 25
  • 1999 F53 belt routing.JPG
    1999 F53 belt routing.JPG
    37.8 KB · Views: 22
  • 1999 V10 pulley.jpg
    1999 V10 pulley.jpg
    173.3 KB · Views: 23
  • pulleymount2000.JPG
    pulleymount2000.JPG
    65.9 KB · Views: 22
I just checked my 2010 (2009 chassis) and mine does not have the additional pulley although there appears to be room for one as well as the bolt hole mount for one already exists. On a similar thought, a vibrating belt certainly could wear unevenly which could be responsible for the original belt's condition. Similar to a tire out of balance, the wear pattern is different than that of a balanced tire. If I ever encounter this issue, I may be inclined to add the second idler pulley as I see nothing in the way in doing so although I suspect the belts are better now days which may be why the second idler pulley is no longer installed by default. ~CA
 
I'm somewhat familiar with the 2005-2009 Ford Mustangs. There were items originally supplied on the 2005 cars but deleted from those cars during that time frame, such as midships exhaust pipe hangers, valve cover oil fill pipes, floor pan braces, etc. that it is logical to assume were cost reductions. Someone determined those items were not really necessary and no one would notice. I'm thinking the same thing happened to the left side idler.


.
 
Bullitt6283 said:
I'm somewhat familiar with the 2005-2009 Ford Mustangs. There were items originally supplied on the 2005 cars but deleted from those cars during that time frame, such as midships exhaust pipe hangers, valve cover oil fill pipes, floor pan braces, etc. that it is logical to assume were cost reductions. Someone determined those items were not really necessary and no one would notice. I'm thinking the same thing happened to the left side idler.
Click to expand...

x2. You make a compelling argument.
 
We have a 2018 Greyhawk 29MV we also have the same issue Had it since new as well. will be on the side lines to see how it goes on here since the rig is all wrapped up for the winter next trip in February to GA from MA have to check it out then
 
Anybody got a part number for that "missing" idler pulley? I would SERIOUSLY consider installing that when/if I get to tear into mine in the next week or so...

I agree with the theory that some bean counter at Ford said "where can we cut costs?" And some engineer said "well, this idler isn't REALLY required, and it'll save us 20 bucks an engine...". Bean counter says "cut it!".
 
I know this is slim evidence, but there's a website that publishes serpentine belt install diagrams.
Serpentine Belt Diagram
According to that, the pulley was deleted for MY 1999.
If this is true, a search of auto parts sites might give the answer regarding part numbers.
 

Attachments

  • 1998Belt.jpg
    1998Belt.jpg
    25.7 KB · Views: 8
  • 1999Belt.jpg
    1999Belt.jpg
    25.8 KB · Views: 8
Last edited:
Have a 2018 Greyhawk 29MV and also have the same issue. Has 2017 Chassis and the issues started after the second season. Happens at 2100 RPM can you can feather it away with a the accelerator or hold it there and make it squeal. Interesting video and I agree a bean counter at Ford is trying to cut cost most likely because to wont fail under warranty and when you bring it to the dealer they wont find it or if they do they don't have authorization to fix it.....
 
If you go to rockauto and filter down to Ford->2002->E450->6.8 v10->Idler pulley you'll see the AC Delco part 38001. If you then go to 2018 (same path) you'll see the exact same part. Seems like its the same pulley across all the engines, either side of the engine. In some diagrams that don't have the part numbers they still reference the two pulleys (one pulley missing in later models) the same "idler pulley".

$15 at rockauto.com, $26 at autozone
ACDelco Idler Pulley 38001
https://www.autozone.com/external-engine/idler-pulley/acdelco-idler-pulley-38001/626191_0_0

I can't seem to find the bolt though.

For ~$20 not a bad bet as long as it doesn't move the belt too much to cause the tensioner to be inflexible. There should be some give there and the current part number belts may not be long enough to allow it.

I'm just going to see what mine does now that the sound is gone and I used a non-Motorcraft belt and what others report if/when they change their belt before I add something in.

I usually make more trouble fixing something that ain't broke (anymore).
 
mini4mw said:
Ever since it was new, the RV would have a fast rattle in the engine compartment when accelerating between 1800-2400 RPM, mostly 2nd gear, 30-45MPH. Sometimes it would happen for a second or two, other times for several seconds. Seems since it has got colder it doesn't happen as often. It wouldn't happen throughout the entire RPM distance, but it would almost always be there, usually ~2100RPM. Let go of the throttle or when it shifts and the rattle goes away. After 12k miles I finally decided to start trying to figure out what it was. Engine runs fine, no power loss, no mis-fires. Its not bad gas as I've gone through plenty of tanks. I stuck a gopro off the radiator and captured the below.

https://youtu.be/Oa6cr2dFkPE

You can hear the rattle start at :15 and then watch the belt vibrate erratically until you don't even see it for a few seconds. Rattle slows down and belt goes back to normal.

What is the cause of this? Bad belt? Bad tensioner? Pulley out of alignment? Something else? I'd think worst case is premature belt failure, right?

thanks-
Click to expand...

Me too! Please keep us posted. I’ve been bothered with the same sound since new!
 

Attachments

  • forum.JPG
    forum.JPG
    42.8 KB · Views: 27
Last edited:
It almost sounds like the old days before knock sensors but not sure timing knock is an issue any more. But I research that, timing may be too far advanced somehow.
 
You must log in or register to reply here.

Similar threads

Freeman-JAY
Locusts
RogerR-JAY
RogerR-JAY
MC
Where are you Camping this week?
TMTEX
TM
don_kleinschnitz
Trip report: to St. Louis and back
drmike961
DR
CL
Check engine light - No exhaust brake
SloPoke-TC
SloPoke-TC
MA
Bunch of questions
Mahatnmacoat
MA

New posts

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top Bottom