Probably coming from throttle body. Make sure bolts are tightened from TB to manifold. If they are tight, change the gasket from TB to manifold for $1.50. Had the same problem and gasket change solved the problem.

 

Thia isnt a help to your problem but the jeep is an Inline 6 not a V6.

My 4.7 V8 has a bit of a whine/whistle after i turn it off and is especially loud if i have the resonator box off the throttle body. I agree with the above post. Check your TB.

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Thanks Nick for the information, I will definitely check that! Man that would be a cheap fix!

 

It's the intake manifold gasket. This particular part is integrated with the exhaust manifold, so it's a joy to replace.

Here's your sound, right?

Not an easy fix but I believe the part is cheap. Not critial to fix either but it may eventually throw a CEL code. It stops when warm because the parts shift and expand a bit with the heat.

 

Ahem....

 

That's it! Is it difficult to get to the gasket? What's involved in replacing it? Thanks Much for the help!

 

Ok... I replaced the throttle body gasket and the sound is still there??? No difference AT ALL! But the whistle sounds like it is definitely coming from that area... Is there any other gasket besides the one pictured that I've missed?

 

I think that I've just realized that it's not the throttle body gasket that I needed to replace but its the Intake Manifold Gasket... I knew that was too easy, because it only took about 5 minutes to replace it... This is the gasket that I need to replace right?

 

Yep.

 

Maybe try retorquing the bolts first. The tough part of replacing the gasket is unbolting the exhaust.

 

Sorry Double E...You did tell me to replace the Intake Manifold Gasket....I guess I misunderstood what that was...I'm a little slow sometimes...thanks again for the Info...

 

I need to do this. Sounds like a real PITA. So ill probably put it off for a while, unless I get into one of those wrenching moods.

 

Finally a solution to the squealing problem! I've been trying to find someone who knows what that noise is for months! Thanks I'm gonna have to do this eventually just to stop that annoying squealing!

 

Iv heard simply tightening the rear intake manifold bolts a quarter turn would do the trick. might want to try that before pulling it completely off I will try mine tomorrow

 

I've had this annoying whistling sound for the better part of a year and it has now stopped with the help (once again) of the forum. I didn't spend much time searching for a vacuum leak - that's exactly what I assumed it was by the way it manifests itself, I just searched the topics here. This solution is in several other threads on the forum. Generally mine would whistle near the drivers side at the firewall while on the highway around 2k RPM with the throttle cracked open slightly while maintaining around 60-70 MPH. Varying the throttle would cause the sound to come and go. Bottom line is that tightening the last two exhaust/intake bolt/nut combos #9 bolt and #10 nut (both 9/16") near the firewall drivers side to 23 lbft solved my problem. The nut on the bottom rear was the loosest and took about 1/4 turn to tighten to torque spec. You will need a 9/16" deep socket for the nut at the rearmost position. Start with re-torquing long before replacing the gasket. BTW - I have a 2001 Cherokee Sport 4.0 175k miles.