Another noise from under my TJ

[TerryMason]

You guys did such a good job diagnosing the "laughing monkeys" that I'm back with another.

Driving down the road in my 2005 Jeep TJ 4.0L automatic. When going around 50 mph, and with a wall or car next to me, I'll hear what to me sounds like a paper flapping in the breeze. It only happens when I'm pressing the gas, and stops immediately if I take my foot off the accelerator.

Driving down the road with nothing next to me to reflect the sound and I can't really hear anything (it's much quieter).

The sound in person is more rattle-y than the video lets on. In the video it sounds like a higher pitch moan.

What do you guys think, could this be a transfer case chain? This is easily reproducible, and since it's been happening I've removed the front driveshaft, and replaced my oil pump / OPDA.

 

[JPNinPA]

I would check how much engine and trans movement you have under load. Stopped, foot on brake, go from drive to reverse and back while watching how much the engine rocks. It could be the u-joints when the engine is out of alignment from wirn motor mounts.
Also check rear control arms. For the same reason. The rear axel may be torquing from a relaxed position to a position placing pressure on the u-joints.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[TerryMason]

I have brown dog extended engine mounts, so I went to roll around under my Jeep and take a look at them when I saw this.

I'm not sure if it's the cause or the symptom but it certainly isn't right. I've ordered a new (used) OEM shroud off eBay, but I may try running without one until it gets here to see if the noise goes away.

Looks like your guess of engine movement may be spot on.

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