yes but why would you leave it loose?
Check the tensioner on that belt it has to be adjusted properly too tight or loose can cause noise or premature failure.
loose timing belt, low transmission fluid in transaxle.
sounds like the alternator belt is loose, check it out and let me know.
Usually a bad bearing or loose belt.
The high-pitched whining noise in a 2009 Jetta can be attributed to several potential issues, such as a failing alternator, worn-out serpentine belt, or issues with the power steering pump. The alternator may produce a whining sound if its bearings are worn, while a loose or damaged serpentine belt can create a high-pitched noise when it slips. Additionally, if the power steering fluid is low or the pump is malfunctioning, it can also generate a whining sound. It’s advisable to have a mechanic inspect the vehicle to pinpoint and address the exact cause.
The belt(s) are probably too loose or too tight. Either way will cause noise.
Loose or worn belt(s).
Loose, or worn out.
You did not mentioned the fan belt. That is the usual cause.
A high-pitch whining noise in a car can be caused by several factors, including a worn or loose serpentine belt, which may slip against pulleys. It can also indicate issues with the alternator, power steering pump, or transmission, particularly if the noise changes with acceleration. Additionally, low fluid levels in the power steering or transmission can contribute to such noises. Regular maintenance and inspection can help identify and resolve these issues.
The belt may be loose or worn.
you probably need to replace a serpentine belt or a tensioner. check your belt and pulleys for abnormal wear and proper tension