In fact, there can be many reasons, it is quite difficult to determine the problem by ear, a thorough diagnosis is needed. The noise of the car engine can be caused by various reasons - an extended alternator belt, a malfunction of the cooling system pump, problems in the operation of the ignition system and/or the fuel supply system, elements. I had a similar noise on my Silverado, but after 5.3 vortec performance upgrades, all the problems disappeared, I found
https://nashvilleperformance.com/sil...ance-upgrades/ a huge amount of information on how to improve my engine better.