Whistling from engine.

[scorpo8972]

I noticed in winter that when I accelerate from startup this whistling sound starts and only stops when i let off the gas. I do have an exhaust leak from exhaust manifold at #8 cylinder. So I was wondering did anyone experience this and is it related to exhaust leak?

 

[Number4]

This is a 4.6l engine symptom. No one to my knowledge has ever directly found the cause. I can tell you for certain, it isn't due to Cold Air Intakes or filters of the such.
Mine does it at times, yet I don't suffer any MPG's so I'm not sure it's an issue other than the sound is annoying.
To me, it's the sound caused by air flowing over an object with an edge to it. Perhaps when the throttle air valve is tilted at a specific angle and the air is coming across it?

 

[05XLimited]

I also have this noise when it is very cold outside, usually <18˚ F. It has to deal with the throttle body and the density of the air. When you floor it, the noise should go away. I don't have any exhaust leaks (that I know of), and it has done it since the time I bought it.

 

[scorpo8972]

I also have this noise when it is very cold outside, usually <18˚ F. It has to deal with the throttle body and the density of the air. When you floor it, the noise should go away. I don't have any exhaust leaks (that I know of), and it has done it since the time I bought it.

It only happens at startup from a nice long nap (8hrs) and when I accelerate thats when it happens and it gets worst and disappears if I do decide to hit 3000rpm. I generally shift between 1.5k-2k on the tach. Only 3k-4k if some ass doesnt want to let me in on the highway.

 

[scorpo8972]

This is a 4.6l engine symptom. No one to my knowledge has ever directly found the cause. I can tell you for certain, it isn't due to Cold Air Intakes or filters of the such.
Mine does it at times, yet I don't suffer any MPG's so I'm not sure it's an issue other than the sound is annoying.
To me, it's the sound caused by air flowing over an object with an edge to it. Perhaps when the throttle air valve is tilted at a specific angle and the air is coming across it?

The funny thing is that it never happened until last winter Feb 2013. It has beeen a nusiance when I carry passengers but doesn't bother me when I'm alone as I'm playing music. It's irritating when you combine the exhaust leak tick tick tick at startup, then the wine with rear diff howl and a new rattling noise coming from the mid-rear.

 

[scorpo8972]

This is a 4.6l engine symptom. No one to my knowledge has ever directly found the cause. I can tell you for certain, it isn't due to Cold Air Intakes or filters of the such.
Mine does it at times, yet I don't suffer any MPG's so I'm not sure it's an issue other than the sound is annoying.
To me, it's the sound caused by air flowing over an object with an edge to it. Perhaps when the throttle air valve is tilted at a specific angle and the air is coming across it?

I also have to agree on the Intake as I do have K&n cold air intake however that was installed july 2013 while the sound only happens around Dec-Feb since Feb 2013.