High pitch sound could be your superchager. Turbo's shoot out a spit of air sound. Maybe your jetta is supercharged stock. Espically if its a tiptronic transmission.
The kids in the back.
Probably your alternater on its way out.
if it sounds like a high pitched whining then it may just be your cool air intake
Fan belt slipping
If the RPMs in the engine increases and the speed not, the clutch may be worn out, usually it becomes noise at the same time
Whining noise near belts had pulleys adjusted any idea what is causing this
A whining noise in the transmission is usually an indication the transmission fluid is low. Check the transmission fluid and fill it to the recommended level.
Could be a tired power steering pump or simply low on p/s fluid.
If a wheel bearing is bad you will hear a howling noise while your driving.
It is the alternator....
Its could be the turbo your hearing...
wheel bearing, gearbox or wind noise Supercharger?