So lately, I've noticed that after I start my truck in the morning, I get this odd whistling sound. The throttle can affect the sound, and eventually the sound does go away.

The best comparison that I can think of for this sound, is blowing into the top of an empty bottle.

It's not really bothering me, but I just wondered if anyone had any idea what this could be.

 

sounds like your air intake.

check all the connections. especially the one near the drivers fender. most likely though it's just the plastic is cold and the air flow. did it do it when the weather was warm?



could also consider getting a CAI...then the noise you hear will be a roar instead of a whistle.

 

Never did it when the weather was warm, but when I mentioned this at the dealership, they found a TSB on the problem.
Something about the idler pulley. I'll find it in a minute.

 

Well I can't seem to find the TSB on the site, but I'll make sure I get the TSB number when I have it fixed.
I simply mentioned the whistling while I took my truck in for a different reason, and they jumped all over it. Within 2 seconds, they told me that there was a TSB and they might as well do it while the truck was in.

And I can't quite remember the full details, but it had something to do with the groove in the idler pulley.

 

cool. hope they are right

 

As do I.
Although I don't really expect much from them after the slight "Misdiagnosis" as they call it.
As stated in another thread, I've been having issues with my door sensor not knowing when the door is open. When I showed him this, he thought that it was just that the radio wouldn't shut off.
I had to physically show him that when you open the passenger door, the door ajar chimes and the lights come on. Then I had him open the drivers door to see if it did the same thing, and to his (actual) surprise it didn't.
He thought that they were just going to replace the radio. I told him door sensors.

So hopefully, they are right. Otherwise I'm just getting new parts for no reason.

 

Please let us know what they exactly did if they do get the whistle fixed. i have the same problem, and it does annoy me. I have heard everything from air intake, (took mine off, still did it) to alternator bearings, now to a TSB that describes the noise and a fix. If I could figure out where it was coming from, I would fix it ASAP. Drives me nuts in the morning, mine is loud, Just as you described though, like blowing accross the top of a coke bottle.

Thanks