A whine type noise may develop form the engine area when the car is idling (typically in warmer temperatures, after the engine has warmed up). It's possible that the noise may be from the engine oil system and is harmless. Still, have a technician verify that the noise is nothing to worry about.Google+
Car Problem Reports
Chrysler 300 Engine Whine Noise Under Hot Idle Conditions
Chrysler 300 Problem
Engines Affected: 2.7L V6, 3.5L V6, 5.7L V8 HEMI, 6.1L V8
Average Mileage: 83,135 mi (10,000 mi - 200,000 mi)
Visitor, 2006 Chrysler 300, 3.5L V6, 58,000 mi
remove foot from accelerator, whine initiates, tone changes as engine downshifts, remains at idle, goes away while accelerating.
Visitor, 2006 Chrysler 300, 3.5L V6, 81,000 mi
the engine is so loud while just sitting that it frienghtens me to thank that the engine may blow up especially when the air conditional is on and the car on and sitting
when am driving i here a squekey noise coming from the ingine. about 20 mins later well am driving it comes off. then it comes back when i start the car.