Every time I go to accelerate my xj is making a whistling noise I've checked the exhaust for leaks and nothing. The weird part is it only happens when it's in drive neutral nothing happens has anybody heard of this before?

 

Any idea where it's coming from? Engine? Rear? Radio?

 

Sounds like the rear or right under the center counsel I hope not trans.

 

I've been looking into this problem more could the torque converter be a possible cause?

 

Vacuum leak sounds like to me

 

But what could it be I hear it around the trans area

 

Wish my cherokee had a turbo jk what color is you're tranny fluid and how full is it

 

Haha I couldn't agree more but it's a pretty expensive setup I've looked Into it haha and clean new actually just did a trans flush about and oil change ago

 

Inspect the vacuum lines that control the HVAC mode and blend doors, those are around the transmission hump under the dash.

 

Inside the car underage dash?

 

Yep

 

Okay I will look today but this only happens under acceleration how is the hvac system related?

 

It's vacuum operated from intake manifold vacuum.

 

Also I'm not sure if it matters like I said before its only under accelaration

 

Generally (not always) vacuum-related leaks which cause a whistling are more pronounced at closed throttle when the engine is making the most vacuum. There is a fairly common "tea kettle" whistle that many get from intake manifold leaks, but again, it usually shows up at idle. In my case, it showed up precisely at the moment I pulled up to the drive-thru window at McDonald's to order lunch. Loud as hell and quite embarrassing.

That being said, it's almost surely vacuum related, even if it's not at idle. XJ's make a symphony of various noises. Squeaking, rumbling, grinding, flapping, ticking, etc. But whistling is almost always vacuum related.