How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Chris (aka- Moose) Your Own Question
Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 48324
Experience:  16 years experience
Type Your Ford Question Here...
Chris (aka- Moose) is online now
A new question is answered every 9 seconds

I have a 2012 E450 Super Duty as the drive train for my

Customer Question

I have a 2012 E450 Super Duty as the drive train for my motor home.
We have a sound that comes out from the engine that is rather like a sawing sound or a pump oscillating sound. sort of a high low repeating sound.
I only occurs at around 30 or 40 mpg and upwards, but always cuts out abruptly when I slow down to stop at around 20 mpg.
The sound doesn't change with speed, its a constant. We can't figure it out, since its not there at idle speeds. It used to be intermittent, but this summer it has pretty well be constant.
Any idea what I should be looking for?
Submitted: 11 months ago.
Category: Ford
Expert:  Chris (aka- Moose) replied 11 months ago.

Welcome, I'm Chris (aka Moose) I prefer to work when others don't, I am here around lunch and after dinner till after midnight.

Can I get that recording uploaded here?

When the noise occurs do the engine, transmission or brakes act different?

Customer: replied 11 months ago.
No, that is why we have been puzzled, there is no apparent difference to the running for the engine. I remember this summer going through some road construction with the window down, the sound bounced off the concrete bollards and was quite loud. In cab its relatively quiet, and hard to figure out exactly where its coming from. When we slow down, it just cuts out altogether.I have a recording on my iPhone Voice Memo, I'll have to see if I can extract it, and add it here.
Expert:  Chris (aka- Moose) replied 11 months ago.

You can upload that file to you tube.

Is there a sound of something you have around the house that I can imagine in my head that your hearing?

Once up to speed and occurring if you shift to neutral, does it still occur?

Any concerns with the tires wearing odd?

I need to run for a while but will return.

Customer: replied 11 months ago. tried uploading various formats for sound, but the system gives me an unknown error. So I have uploaded a Windows file to my Drop Box, for you to download and listen to.There is road noise, as we are driving at the time, but you can hear the higher pitch see-saw noise, or a drying out pump? Kinda sounds like a pump with no oil in it.I haven't tried going into neutral while driving, that hadn't occurred to me. we only have 38,000 on this rig, and the pitch doesn't change with speed or gears, so I ruled out fan belts and wheels. I'm just not sure what kind of pump kicks in around 30 - 50mpg, and kicks off when going less than 20.
Expert:  Chris (aka- Moose) replied 11 months ago.

I can hear it, kind of a high pitched noise that goes up and down. It for sure sounds like something spinning but it is something that is spinning slow which rules out alot of parts.

Try neutral for me and try changing the blower speeds?

Turn the fan clutch by hand with the engine off to make sure there is some resistance but no noise or wobble.

Customer: replied 11 months ago.
I tried rotating the fan, once I figured out where it was, pretty tight in there. It rotates with resistance, but no wobble or noise.We drove it to the winter storage yard last night, but the journey wasn't long enough for the noise to start up, so I can't comment on the other ideas.It is winterized now, so I doubt we'll have it out on the road again this year. Obviously you are as puzzled as we are. Any ideas at all that I can put into a list to check for?I'll save this link for the Spring, when we'll have it out again.. and no doubt the sound will join us again!Cheers, Neill
Expert:  Chris (aka- Moose) replied 11 months ago.

When out of storage I would drive it till it occurs then stop and remove the belt. Then drive a max of 4 minutes. If the noise is gone then it is for sure going to be something that is spinning and related to the belt. That will help rule out many possible causes or allow you to put more focus on a specific area.

Customer: replied 11 months ago.
You say, remove belt. Now you scare me.. which belt are you talking about. I thought there was only one main serpentine belt. Is there another?
Expert:  Chris (aka- Moose) replied 11 months ago.

There is only one belt.

Expert:  Chris (aka- Moose) replied 11 months ago.

Hello again Chris here,

  • I am following up with you to see if you got everything you needed from my answer.
  • I have not heard back from you, so I assume you were not pleased. We're you pleased with my help?
  • If you were not pleased with my help, please let me know by replying so I can help more.
  • This post is coming up on the 7 day mark where it times out. When a post times out, that means it's no longer on my active list (you reply and I may never know it.)

Thanks Chris

Customer: replied 11 months ago.
Doesn't removing the belt prevent you from starting the engine and running it? I wasn't aware you could run an engine without the belt? Or am I old school?
Expert:  Chris (aka- Moose) replied 11 months ago.

You can remove the belt and start the engine, but only run it a max of 4 minutes or less because the water pump is not spinning, so you do not want to overheat the engine. You could actually take the belt off and make it about 50 miles if driven carefully and you shut it off often. Eventually though the battery would run out of power because the alternator would not be running. This is just a test to see if the noise is from a pulley being spun.

Customer: replied 11 months ago.
ok, didn't know that.. that would be a pain to put back on. The reason I dismissed that concept, was because the pitch doesn't change with the speed of the engine. So I would have thought would be the same for anything else on the pulley? But for a process of elimination, I'll read up on belt removal and replacement, so I'm confident how to do that before attempting it.
Expert:  Chris (aka- Moose) replied 11 months ago.