Engine noise plz help

[Jctomas25]

I am getting this engine noise from, what seems to be, the front, top left part of the engine. It usually happens at low idle, under light load at initial start of a cold engine. It initially sounds like a pulley bearing. I am thinking maybe the Alternator. No codes or anything attributing. Replaced both pulleys and tensioner pulley unit and it’s just getting worse. Can’t pinpoint this sound and don’t understand why it only happens at initial startup on cold engine then dissipates as it warms up. Any ideas?
When the AC compressor engages creating a load, the noise gets louder, then fades away slightly when the compressor disengages. And goes away completely when up to temp.
Definitely more noticeable front left side. It’s not exhaust.

 

[BLACKJKU]

What year is the Jeep?

Take your serpentine belt off and start it up and then listen for the noise.

 

[Jctomas25]

I am getting this engine noise from, what seems to be, the front, top left part of the engine. It usually happens at low idle, under light load at initial start of a cold engine. It initially sounds like a pulley bearing. I am thinking maybe the Alternator. No codes or anything attributing. Replaced both pulleys and tensioner pulley unit and it’s just getting worse. Can’t pinpoint this sound and don’t understand why it only happens at initial startup on cold engine then dissipates as it warms up. Any ideas?
When the AC compressor engages creating a load, the noise gets louder, then fades away slightly when the compressor disengages. And goes away completely when up to temp.
Definitely more noticeable front left side. It’s not exhaust.

What year is the Jeep?

Take your serpentine belt off and start it up and then listen for the noise.

2013 Unl Rubi10A 3.6L

 

[BLACKJKU]

2013 Unl Rubi10A 3.6L

Take your belt off and run it just to eliminate anything that is belt driven, don't run it to long so that it gets to hot.

 

[Snowbird Tom]

Take your belt off and run it just to eliminate anything that is belt driven, don't run it to long so that it gets to hot.

Yup, should only take a couple minutes with the hood up. Start, jump out and listen for the noise, shut down.

 

[vaffanculo]

I am getting this engine noise from, what seems to be, the front, top left part of the engine. It usually happens at low idle, under light load at initial start of a cold engine. It initially sounds like a pulley bearing. I am thinking maybe the Alternator. No codes or anything attributing. Replaced both pulleys and tensioner pulley unit and it’s just getting worse. Can’t pinpoint this sound and don’t understand why it only happens at initial startup on cold engine then dissipates as it warms up. Any ideas?
When the AC compressor engages creating a load, the noise gets louder, then fades away slightly when the compressor disengages. And goes away completely when up to temp.
Definitely more noticeable front left side. It’s not exhaust.

I usually spray the belt and ,pullys with wd40 ..do when the engine is not hot ..or you can just buy belt dressing spray

 

[BLACKJKU]

I usually spray the belt and ,pullys with wd40 ..do when the engine is not hot ..or you can just buy belt dressing spray

That's only for belt noise.