Noise question?

[MikeP]

OK have a question concerning a weird sound that happens off/on. Like when sitting at redlight that road slopes downhill. You let off brake and as rolling forward mostly on vans own momentum while turning you hear a metal on metal scrub sound. Sounds like sound coming from rear of front seats.
It does not happen every time just sometimes, if you accelerate it disappears quickly or does not happen at all.
Sound makes me think of a metal ring on a flagpole that gets moved by wind when flag flaps.

Van is 2003 140 Super Tall Passenger Model. We are original owners it has 41K miles. It's pretty loaded with rear-entry wheelchair lift and most time 2 full rehab chairs loaded above and to front of rear axle.
Any ideas or suggestions?
"Thank you!"

 

[NelsonSprinter]

I would look at the driveshaft hangar bearing for wear, something may be touching the driveshaft or hangar bearing or each other. Not a diagnosis, just a thought since there is a large U around the driveshaft, in case the hangar fails, to catch it, that could make that sound, near that location.

 

[MikeP]

"Thank you!" I never seen under van so didn't know about the hanger. Makes sense since seems sound coming from back.
I have heard it a few times but never could get it to repeat noise when trying.
But, we were in town this evening and it made noise when pulling in a parking lot. My wife heard it and said is that what you been talking about. I went around block twice but never got the noise again.
It's due maintenance service, we go for oil change at least once a year even though we don't put many miles on it. So will get it checked out when weather clears up some.
"Thanks!"

 

[MikeP]

Sorry, old thread but after first posted had service at dealership and they didn't "find" anything wrong.
Been awhile and noise got my attention again.
Still only dose the noise here and there mostly rolling start when release brakes.
I began to think might have ice somewhere underneath last year since weather and all.
But, noise happened over summer just occasionally, seems mostly after sitting several days without being used.
Since been cold weather again, course limit our driving it a lot more, too. Hear the noise more often, yesterday we were in upper 60's when done it.
If it was while stopping I'd think brake pads or rust on rotors. But starting, usually when just free rolling.
If was driveshaft or rear end would the noise get worst with acceleration or louder when in rull motion?
"Thanks!" And "Sorry" for pulling up old thread. The noise just bugs me.

May not help but telling Mama I was asking on here about "our" noise. She said she thinks it sounds like the brakes on large truck, like dump truck's brakes as it's stopping. But, same noise but on our startup instead of stopping.
"Thanks"

 

[sailquik]

MikeP;
Can you give a better idea what the noise sounds like?
It could be the groaning sound that Sprinter disc brakes make when you ease off the brake pedal and
the pads chatter across the rotors.
If it's a brake squeal, it could be the fairly soft brake rotors and the extremely hard brake pads MB
has used on Sprinters.
They work the best, but the pads and the rotors wear at about the same rate and you get a tiny sharp edge
on the outer rim of the rotors.
Sprinter brakes pretty much all squeal, at times, and while it's embarrassing when I screech up the to sentries
going onto military bases, the brakes work really well and do not fade.
It sure sounds like the grumbling/groaning as the rotors start to turn that's the sound you are getting.
You can duplicate this pretty easily.
When sitting at a stop light with the Sprinter in gear, ease off the brake pedal slightly and you will
hear the grumbling/groaning sound as the rotors turn between the brake pads.
A little more pressure on the pedal and the groaning stops because the rotors are locked.
A little less pressure on the pedal and the groaning stops because the rotor is not running freely.
Hope this helps,
Roger

 

[BlueIce1]

Hi Mike,
Your noise sounds like it might be from the brakes.
When you apply the brakes the pads grab the rotor, when you release the brakes the pads and Pistons get knocked back just enough to clear the disks, by the motion of the disks. If one of your Pistons has some corrosion or or goo or something on it, it may take a little longer for the piston/pad to be pushed back, and you are hearing the pad dragging on the disk until it gets pushed back (or it wears back).
If it is doing it a lot you will get uneven wear on the pads of one brake and it will be easy to find.
I hope you find the cause, intermittent noises are annoying.

 

[MikeP]

You can duplicate this pretty easily.
When sitting at a stop light with the Sprinter in gear, ease off the brake pedal slightly and you will
hear the grumbling/groaning sound as the rotors turn between the brake pads.
A little more pressure on the pedal and the groaning stops because the rotors are locked.
A little less pressure on the pedal and the groaning stops because the rotor is not running freely.
Hope this helps,
Roger

First, "Thank you!"
Yes, it definitely does the groaning if ease up on brake pedal when stopped, where van will roll without holding brake pedal firm. And that noise stops when apply more pressure on brake pedal.
Mama always saying "brakes" when sitting at red-lights if I let it roll any.

But, this bugging noise is when completely let brakes completely off.
Completely off brake pedal but before get pressure on accelerator to be under any engine involved movement to drive-train.
Seems like noise, when it happens lasts maybe two or three rotations of the wheels and it's gone.

What makes me think just makes noise is only on start up rolling. On trips to city over summer I would roll window down when in locations where should get echo bounce back from concrete barriers but don't hear anything.
We have short tunnel under the take-off strip for our local little airport and go through it every trip into town from home. Gone through it at all kinds of different speeds and in all weather situation. Have not heard no sounds of this bugging noise.

If helps we are up to a little over 43K miles now.

 

[MikeP]

Hi Mike,
Your noise sounds like it might be from the brakes.
When you apply the brakes the pads grab the rotor, when you release the brakes the pads and Pistons get knocked back just enough to clear the disks, by the motion of the disks. If one of your Pistons has some corrosion or or goo or something on it, it may take a little longer for the piston/pad to be pushed back, and you are hearing the pad dragging on the disk until it gets pushed back (or it wears back).
If it is doing it a lot you will get uneven wear on the pads of one brake and it will be easy to find.
I hope you find the cause, intermittent noises are annoying.

"Thank you!"
We are due a oil and fuel filter change. Just waiting til our spring gets underway. It's pretty good trip over to dealership. That's why I posted in another thread if anyone knew of place over here that we were in hopes there would be one.
I guess if noise gets worst quickly could get local Dodge place to check it out.
I'll ask dealership when we go over for service to check brake pads.

 

[MercedesGenIn]

I realise this is a very serious noise compared to what you hear but it may lead you to the cause. In this case centre bearing alignment.


Also:

Check for handbrake shoe retaining springs missing or broken, could even be inside the handbrake drum. The pins corrode and fall inside.

Brake disc back plates catching on disc rotors

Dry sliding splines on propshaft centre

All the best
Steve

https://www.youtube.com/watch?v=bhukq8_WDA8

 

[sailquik]

Steve,
Great video!
You can hear the bearing when the drive shaft RPM gets near it's highest.
You can hear the whine from the bad center steady bearing pretty clearly (or at least I can).
What did you take the video with....GoPro or something else?
Guess I need 4 of them...one for each wheel, to demonstrate out of balance.
Thanks,
Roger

 

[MercedesGenIn]

Hi Roger
Not my work I am afraid, I came by this the other day while browsing YouTube.
From reading his notes on the YouTube video it turns out he has an alignment issue with the centre bearing.

Hope it is some help to some one..

I would like you guess a GoPro - who would have considered one of those as a diagnostic tool !

Steve