e-450 engine rattle - serpentine belt

mini4mw

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Mar 23, 2015
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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-
 
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-

I'd contact a FORD dealer since you should a 3 yr/36,000 mi warranty on the chassis.
 
One thing to check is to make sure the crankshaft pulley bolt has not loosened up. There was a recall for it but not sure if your year was affected. The bolt just needs to be checked for proper torque.
 
I haven't noticed that issue on mine, although I will check for it. However, I did have a similar issue on another vehicle and upgraded the belt to a Goodyear Gatorback belt and the issue went away. I would recommend you give that a try before going any deeper. Here is what summitracing states about the Gatorback:

Goodyear Gatorback Poly-V serpentine belts run quieter, stretch less, and transfer more power than other belts. As they warm up, the composite construction between the cords and rubber compound becomes more efficient at turning your engine's accessories. And by absorbing the shock and vibration transmitted from the crank pulley, the belts can help your harmonic damper to better reduce harmful vibrations. Gatorback belts are available in a variety of lengths and rib counts for fitment on hundreds of vehicle applications.
 
Mine makes the same noise like yours. Been doing it almost since it was new. I always wondered what it was. Thanks for the video.
 
Like others have said, make sure all the zerks are greased. The V-10 is an inherently unbalanced engine cause all pistons are not moving exactly opposite each other like in a V-8. The engineers try to keep the vibration at the lower rpm range instead of at cruise rpm, but if the driveshafts are off balance, all kinds of issues can arise.
 
Has anyone tried replacing the tensioner pulley?

I have the EXACT same rattle. Been driving me bonkers since I've owned it. I talked to my dad about it (lifetime mechanic, and has worked on these chassis before), and he said it's not likely the pulley. But I'm not so sure. His point being that if the bearing was going out in the pulley, it would make a more "grinding" noise, then it would fail relatively quickly. Also, if it was a bearing, you'd hear it no matter what RPM the engine was at. Most of us have been dealing with that noise for the entire service life of the vehicle, and it presents at a VERY specific RPM range (~2100 RPM under load seems to be the common denominator). I see his side. But my point is, what if Ford just used a part that was slightly out of spec? What if it's not the bearing going out, just that the pulley is a little loose or wobbly? That could EASILY cause these exact symptoms. It would also have the effect of shortening the life of the bearing...

I've read other's have replaced that pulley (~$60 from Ford) and it went away. For that money, I'm ALMOST willing to take the chance on it. But I haven't gotten up the nerve to start tearing into the engine bay yet. I peeked in there, and I couldn't readily see it. I'd have to pop out some of the cowling under the hood. No big deal to do that, but I just haven't gotten there with this issue yet...

It was a SUPER easy replacement on my Jeep. One bolt. I did it as "preventative" measure on that vehicle, because I didn't want a bearing made 25-30 years ago that was that easy and cheap to replace to leave me stranded one day...

I'm on the absolute edge of my seat to see what the ultimate outcome is on this mystery. Like I said, it's been driving me bonkers since shortly after I brought it home. Just not enough to get to where mini4mw is ... yet...
 
I called a commercial Ford dealer service team near by this morning and I had them review the video. We're going back and forth on email with different questions. I'll update once there's some good info.
 
I have the exact same noise in my 2018 29MV with 8K miles. Happens right around 2100 RPM while on throttle, then goes away by 2300 RPM. Doesn't matter what gear or what speed. At times it seems to be less noticeable, haven't figured out any correlation yet (engine temp, ambient temp, ???) Interestingly, I drove an E450 Uhaul truck this summer that made the same noise, just louder, at the same RPM. I've also seen other reports of this on various MH forums, so seems to be something intrinsic to the E450. Can't believe that Ford doesn't know about it.
 
A couple of years ago, driving on my way back from Detroit to central PA in my Mustang, I started to hear a new noise. I could have sworn it was clutch-related, because every time I applied the least little bit of pressure to the clutch pedal, the noise went away.

As it turns out, the little bit of pressure I applied to the clutch pedal moved the crankshaft the least little bit, and the serpentine belt stopped making the noise. The engine was in great condition, so the movement couldn't have been much.
I really didn't believe this to be possible, until I was showing this to my son (Master ASE).

As the engine was idling, and making the noise, he grabbed a bottle of detail spray off the shelf and squirted the belt. The noise went away immediately.
So, I changed the belt. Problem solved.



Is there something in (any of) the pulleys or driven accessories of the E450 that could change position (fore-aft) in certain circumstances??


.
 
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I did a bunch of searching before posting (or grabbing the video - searching the interwebs actually gave me the idea for the video) and there are lots of posts. Unfortunately engines make all kinds of sounds and screech may be a squeal to someone else and a rattle could be a clank. The hardest part of all of it was trying to narrow down a word for the search that most people may call it ;). If you search for the ford 450 v10 belt and/or serpentine you'll see a lot of people replacing it for similar sounds (belt, tensioner, idle pulleys).

This is why I haven't done anything yet as I knew it was going to be a pain. Used the https://fordcommercialvehiclecenter.com/ to find a dealer that would check it out and after going through 6 dealers around Atlanta finally found one that works (so they say) on RVs over 25' and will take a look. Of course they are 1.5hrs from the house on a good day and I need to get the RV from storage which is another 15-20 in the other direction. Of the previous 6 locations I heard we only have 1 RV tech and they are going on vacation for a few weeks, we do work on RVs but the waiting list is 3 months back, we only work on smaller RVs, we only do RV maintenance, etc. I'm going to try and find time for the 4-5hr round trip next week sometime to have someone 'take a look'. Oye..

If I knew I could replace the belt and tensioner for $200 to make it go away I'd do it on my own.
 
I would consider just changing out the belt if you have the skill set to do so. Your tensioner and idler pulleys are probably still good and imo it is always good to carry a spare belt with you anyway. I didn't find a gatorback belt listed for our V10 engines though, but there are other high quality belts to choose from.
 
Posed with a 4h+ round trip 2x (drop off/pick up) I decided to go ahead and buy a belt and replace it. Initial searches came up with all kinds of different sizes. I found Ford's parts site and it lets you put in your VIN and gives you the exact part number for the replacement which for me was:

Ford/Motorcraft Part #: JK61004B (8620)

https://parts.ford.com/en.html

I took that and searched around. I wanted to drop off the RV as soon as possible at the dealer since my 3yr warranty runs out the beginning in Jan so I was somewhat limited on options - no online orders. (Try and get in line to be fixed before warranty ran out) I also didn't want the hassle of trying to return the belt if it was the wrong size. I bought this one at Autozone:

Continental Part #4060998 - $38

Other options:
Advanced Auto Parts
Gates Automotive K060997HD $55 30 day warranty
Dayco W1000164148DAY $78 1yr warranty

I found an online picture of the belt configuration and printed it out. Surprisingly (to me) it only took maybe 20min to replace it. I was under the chassis and the first/last belt slide was the condenser on the bottom left.
I could get to the belt with one hand and push the tensioner with the other.
A good portion of the 20min was trying to get the belt on from under the hood and under the chassis. Get it on here, comes off over there. I ended up using a little duct tape to keep it in place so it wouldn't come undone in one place while I tried to fit it on another. Two people would make it easier. The belt tensioner needs to be pushed clockwise facing the front of the RV. The belt tensioner needs a 1/2" square fitting. I used a long 1/4" ratchet with a 1/2" adapter. Doesn't fit well between the fan and tensioner (too wide with the adapter) but it worked. I also didn't take off the entire air intake as it shows in some videos, just the filter which comes off very easy. Took it for a 20m test drive and no more rattle!

Attaching some pics below. The fan pulley is worn on the inside, perhaps the belt doesn't sit exactly right and wears unevenly causing the vibration? Also both sides of the belt had some areas where you could see threads and others that you don't. Worn unevenly or defect? I can't remember if it made this sounds since new, but its been there since I can remember. Just put the old belt in a storage bin and will take it along as a spare.
 

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(text deleted for brevity) [url said:
https://youtu.be/Oa6cr2dFkPE[/url]

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-
ROCKAUTO BELTS= $11-$32 and tensioners $23-$43, so order both on the higher quality (since going for noise issues); not too hard a DIY to try a belt and then do tensioner if needed; the experienced mechanic probably 15-minutes, never done before, est= 1-Hour? Maybe load-a tool from parts store if needed? Also let us know condition of old belt, glazed, cracked, chunks missing, etc. Cracks OK per MFR, but... maybe cause noise
 
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My first dealings w/ serpentine was 5+hours/ $600 on a V-6 Lesaber at Dealer included water pump that it probably did not need, and 2nd a f ew years later was a 10-min $30 DIY
 
Okay, so conclusion? For now anyway?

Seems to be belt replacement fixed the issue since that's all that was done.

When I go after mine, I'm probably going to go ahead and replace the tensioner pulley as well I think. Just in case. And because they have been a known issue in the past...

Keep us posted on as long a term as you can so we know if your fix was "permanent"?
 
Yes, issue fixed for now and all that was done was the belt replacement. Drove back to storage (another 20 min drive) and it was still good. It was happening during every acceleration move previously.

The belt is very tight on mine. It took a few tries to get the belt over the condenser pully so I don't believe that is a problem. The other pulleys spun freely and smooth as well.

Now its just a matter of long term waiting/use. Will it come back after a few thousand miles indicating premature wear/alignment issue or is it permanently fixed and it was just a bad belt all along...

I won't have any updates near term as no trips planned till Spring.
 
Thank you!!

I MAY have an opportunity to test out a somewhat long-term solution on this. We're leaving the week between Christmas & New Year's, total drive about 22 hrs on the rig. If I can swing it, I'll try to get a new belt on there before we go, but it's going to be tight time-wise. Don't know that I'll be able to get it done...

Will update here and on my long-term thread when/if I can get it done before the trip. Otherwise it'll be May 2021 before I get to test it out...
 

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