View Full Version : New Noise Only Under Acceleration

10-03-2010, 11:58 AM
My new little hiccup is occasionally when driving down the road I hear a "moan" or a harmonic style sound that matches the rpm load until I accelerate enough for the turbo to ramp up and it's gone but I don't know if it's gone or if its just muffled by the turbo. Any ideas on where to start? I searched the forum
but I can never find anything because I am a quitter. I remember reading something about noisy fuel lines vibrating could that be my problem? Thanks guys.

P.S. Its an 04 regular roof with 95K and more rust than a scrapyard but I love it.

10-03-2010, 01:49 PM
It is possible that it could be the fuel pump relief valve. If it continues to make the noise after the engine has been turned off for just a few seconds then that is probably it.
You can also check it by looking under the drivers side footwell at the fuel lines with the van running and see if the fuel lines are vibrating alot.

The word on it is that you can drive indefinitly with a bad relief valve but the sound, if that's your problem, is really annoying all of the time.
This thread gives a part number for the part and also explains a few other things to check.


I hope this helps


10-04-2010, 11:46 AM

Thanks for responding. It's not fuel pump relief valve I am familiar with that noise. It happens when in a lower gear usually around 23-2500Rpm (not exactly I'm sure) and I go to step on the throttle I press about an inch down and before the turbo kicks in and I get this little harmonic or whine that matches my RPM it's very strange. It is just starting to get cold here and I wonder if that has anything to do with it? Thanks guys

10-04-2010, 09:10 PM
I had the same problem on my 2006 3500, and It turned out to be a cracked hose coming out of the intercooler, also the clamps that hold those hoses on become loose so when the turbo kicks in and pressurizes the tubes, you will hear a air rushing noise either passing thru a loose connection or cracked hose.

10-05-2010, 12:07 AM
I havent had a power loss and over the summer I changed all the turbo plumbing because of a split hose, but I will check in case anything came loose. Today I did do a little screwing around with it... and this is what I found it happens around 1100 rpm up to 2000 rpm at about 25 mph it's strange because it clears up or I don't hear as I get going a little faster, perhaps is tranny related and it's in a different gear?

10-05-2010, 05:18 AM
Could you be experiencing RSN? It's about the right mileage for it to happen and it usually occurs on cold mornings?? Hope this helps.

Thank you, John
Sprinter Store
A division of Upscale Automotive, Inc.
19460 SW 89th Ave.
Tualatin, OR 97062

10-05-2010, 10:40 AM
Noped I have been Darfed and all is good! Better smoother shifting no more rumble strip! I guess I need to do some experimenting in the driveway, I dont know if it happens in park or if has to be rolling but I will report back to you

01-02-2011, 01:17 PM
So the Phantom noise has been absent since I changed the electronic plug that goes into my transmission. I noticed fluid coming out of that plug so I realized the O-rings were bad so I read a couple of posts on how to change it, spent the 9 bucks and swapped it. I did bring the tranny fluid to the correct level and since then have had no funny harmonic noise. It begs the question would that plug with bad O-rings make the low whine/grinding noise or would the transmission with low (but not more than a half of quart) fluid make such a noise?:hmmm:

01-02-2011, 01:28 PM
My guess would be the low fluid.

Aqua Puttana
01-02-2011, 02:09 PM
My guess would be the low fluid.

Can't disagree, but I'm surprised if actually only a half quart low. That is not much level change on the dipstick. Nothing else was changed in the system other than the socket assembly? :idunno: vic

01-02-2011, 04:05 PM

Umm, actually now that you mention it a week before doing the plug I did my normal maintenance... ah poop it could be part of that. Here is the list

Oil and fllter change.
Fuel Filter Change (which I found that one of the clamps on the fuel filter was stripped and really had not been tight for quite a while by the amount of diesel all over the filter, so I changed that as well.)
Air Filter (which had a tear in the rubber seal)
Cabin Filter (I dont think had ever been done)
Topped all fluids and checked for Black death (good to go)

and now I can't remember if the noise was present in between these upgrades and the tranny fix!

Aqua Puttana
01-02-2011, 04:57 PM

Air Filter (which had a tear in the rubber seal)

That could possibly make a buzz noise under high flow rate? vic