just bought my jeep with 215000m replaced the exhaust manifold, had a loud exhaust noise before so the new sound may have not been heard. after 1/4 throttle in the cab you can hear a rapid cricket/bubbly/valve/combustion noise. kindve high pitched and increases with rpm. loudest on the highway of course. Removed belt, sound remains.

things done;

exhaust manifold & pipe to cat
manifold and exhaust smoke tested
valve cover gasket
checked torque conv bolts
rear end and wheel bearings are fine.

my only guess would be distributor shaft noise? but it sounds so valve-ey but not a tick.
video link:

 

Couldnt hear it all that well. Thought i heard a faint squeak at the 2 second mark. After that i heard what sounded like something rattling, maybe? Couldve been road noise. I had a faint squeak with my 97 i could hear with the hood up. I traced most of that to the distributor shaft, which was loose. There was a tiny tiny bit coming from the belt tensioner pulley also. I had another faint squeak that i could hear inside the cabin. I traced that to the transfer case linkage. It would stop when i held the shifter.

Can you hear it idling, or with the hood up while giving it gas?

 

 

Harmonic balancer going hooves up?

 

 

Manifold-to-exhaust pipe donut gasket?

I've listened several times to the video but could not discern any noise as you describe it. Is the frequency of the noise rhythm in keeping with the firing of the cylinders at idle and increasing with RPM?

 

 

Compression tested?

 

 

My have zero relevance, but it's a good watch.

 

 

Heat shield on any part of the exhaust or on the exhaust side of the engine bay?