Whistling/Whining Noise

[brokenujoint]

did you find the cause?

[cr0sh]

I know this is an old and likely dead thread, but the OP's problem sounded very similar to the one I had on my (new to me) TJ earlier this year just after I got it. Basically, I'd start it, and it would warm up. Once it was at operating temp (about a mile or so away from home), it would make this awfully loud whistle - it honestly sounded like the devil's teakettle. But only at idle; give it some gas, it'd go away. Let it idle, back again. It would stay this way for a couple of minute, then go away for good - I wouldn't hear it again until the next morning when I started her back up.

I cleaned the throttle body (it needed it), but no dice. I tried cleaning the IAC (and in the process found that the gasket was unobtanium - so I had to make my own!) - still no dice. I tried replacing the IAC - that didn't work either. At a loss, I finally took it to my mechanic. On the morning on my way there, it did it again. I pulled over and listened real carefully before it went away - and I had this feeling that it might be the belt tensioner; it seemed to have a slight metallic sound to it...

Got it over to my mechanic, and he looked at it (plus got a few other things fixed as well that were needed - $$$) - and guess what? It was the tensioner.

He replaced that, the noise hasn't come back since (about 5 months now).

So listen to it carefully - and try replacing that part; it's cheap and easy to do (I'd have tried it myself if I didn't have other things on it that needed repair - like the rear main seal, and some other stuff - like I said, $$$). Worth a shot if you don't have anything else wrong you need a mechanic to look at, and it beats having him do it and getting charged for it.

[chad1]

Got the same issue and the culprit was loose bolts on the intake manifold.