Whistle noise here when accellerating only.

[dadr99]

my 01 xlt just developed the same whistle,mostly just at take off with a cold engine and cold outside temps.i never had this noise until i replaced a dirty air filter,also there is a black plastic cap on the idle air control valve which hides a small filter,i've heard of those making strange sounds when they get dirty also.just a few thoughts to help out.

 

[Dibbs40]

my 05 xlt developed the same whistle/whinning noise, few weeks later the transmission started slipping between 3rd and drive and a few weeks after that I had to have the tranny replaced. The new tranny fixed the noise that would increase in volume when I accelerated. I wish the fix was as easy as replacing the air filter or air control valve filter.

 

[Campnham]

I have the cold whistle also. I just turn up the radio
Had it for 8 years...

 

[crjmaso1]

Got the whistle in my 03 Explorer 4.6 as well. Although it only happens when the outside temp is below 40f. Right around 1800-2000 rpms and goes away upon higher rpms. Have not found the cause either, I just tell people its a turbo! Does not seem to effect the engine at all, just rather annoying after awhile.

 

[player12]

2002 Explorer Sport with 170k. Mine whistles when cold under acceleration.

 

[big04explorer]

I have a 04 4.0L and mine just started recently only when I'm on the gas around 2200-3000 rpm. It almost sounds like a turbo, I'm not complaining but it has affected my mpg and idle.

 

[Bobmbx]

There are several causes. It could be your IAC (it has a little vent on it), or a loose vacuum line, most often its a hose on the intake.

Odds are you'll never find it. Its a pretty common complaint.

 

[rewind1]

I had this problem 3 years ago, it was coming from my PCV hose I think. It was one of the first repairs I did to my Ex, so its hard to remember. It was definitely related to the Pressure Control Valve on the passenger side though. I remember there was a hole so I put tape on it for a while until it started making the noise again, then I replaced it. It was definitely worse when it was colder out.

Mine is a V8 but a quick google search showed me lots of V6 with the same issue.

 

[1RadCJ5]

Hi all - I have an 02 Sport Trac 4.0. I've owned it for 7 years here in Maine, but truck was originally from Florida. Bought with 69,000 miles, and only has 122,000 now. I have always heard that very loud annoying whine around 2,000 rpm, light throttle load, only when winter\cold weather is upon us. Usually, once all warms up under hood in very low temps, sound goes away. It's been like this since I've owned it. Like others, let up or accelerate, and whistle stops for a short bit. Summertime, never ever hear it. Park in a heated garage, noise never happens. Park in unheated garage, noise is there until engine warms up. I am certain after 7 years that it's not a major issue. Have never had a check engine light, but sure would love to know where this little demon sound is coming from.... Its not a belt, I change it every few years, last being around Christmas 2018. I also changed the belt tensioner and idler pulley while I was in there.. Wish someone had that "AHA" moment, lol. Oh well, spring is just a few months away, 40 degrees or more, and no whistle all summer long! Mike