That is the answer to your question. Don't know why, but the noise is caused by air getting trapped in your fuel system. With your truck running and making the noise, pop the hood and put your hand on the top-side fuel filter. I will be very noticeably vibrating, especially on the fuel supply line. Both my 6.7's have done this from time to time, only solution I have been able to come up with is to remove the fuel filters and purge the system as you would if you were installing new filters.

 

my 2012 has always done this, just thought it was normal.

 

It's not normal at all. Will some of you all confirm that when in park and you tap the throttle to about 1500 rpm and release it quick the sound goes away.

 

It's extremely normal.

 

I've hag 2 other 6.7 that did not do this.

 

Hey, folks!

If you're ever concerned about a noise that your truck is making, it's best to have your dealer listen to it to determine if it's normal. I'm always happy to do what I can to help as well.

Crystal

 

Just a thought, my 2013 always had a vacuum when I removed the fuel cap does anyone else have that? I was told that these fuel systems do not build or have vacuum as they are vented. So could this wining possibly be air being suck by if the tank is under a vacuum.
Just a thought.

 

Yes, my whine would disappear when you tap the throttle just off idle - didn't need to get to 1500 RPM, maybe 100 RPM above idle. Whine would return when engine dropped back to idle. As I stated in my previous post, I resolved mine by replacing the fuel filters.


As a side note, when mine originally started whining, it was right after a very hard acceleration while towing my trailer. Did it for about a year until I changed the filters.

 

I wonder if the venting is just not adequate - not completely blocked as yours would have to have been to have vacuum in the tank every time you remove the fuel cap. As I mentioned earlier, mine started whining after a very hard acceleration while towing. I wonder if under high fuel draw, it could suck some air due to insufficient venting of the tank. Just a possible theory.

 

I fill up all the time while idling, and the whine does not go away.

 

I'm not saying for certain that air in the system is the cause of your whine, but I think you might be missing the point here. If at some point the tank went into a vacuum, air might have sucked into the fuel system and gotten trapped in a high place within the fuel system. If that happened, then it wouldn't necessarily matter that your whine doesn't go away when filling up with the engine running (the air is already in the system and can't purge itself out). This is speculation - just a possible theory that incorporates both the fact that some people have resolved the whine by replacing the filters/purging the system, and others have reported vacuum in the tank.

 

10-4. No vac issue here. Also, the highest point of the fuel system is the filter under the hood. It is installed, as far as I know, full of air. Seems most trucks purge it. I am leaning towards a solinoid in the exhaust or fuel system.

 

Yes, I know the underhood filter would likely be the highest place in the system and that it is installed dry, and that the system can purge the air out when following the purge procedure outlined in the manual. Just out of curiosity, try running through the purge procedure and see if the whine goes away. In hindsight, I wish I had tried that on mine before replacing the filters.

 

Not familiar with a purge procedure. I'll google..

 

nothing more than key on, key off.


6-8 times.


turn the key on till the buzz stops.