Strange noise from engine compartment

Posting for a friend.

He has a strange "whirring / chirping" noise coming from the engine compartment from the back of the engine. He said it sounds like it is below the fuel rail. I have no experience with the cracks in the manifold etc so not sure if that could be it or not. it only happens when the engine is cold or has been off for a bit. after about 15 minutes it goes away. it seems to be louder under a load.

any ideas?

:dunno:

SEARCH "angry sparrows"

Jeep is not moving so it is not driveline related. I guess i should have clearified that. it happens at startup in park during idle with cold engine or happens when under load. I did search and nothing was found that seemed to fit. I always search first. but thanks for the heads up on the "angry sparrows" it is good info if ever i have drivetrain noise.