Please fill out the following to ask a question. MAKE: Chevrolet MODEL: Malibu YEAR: 2005 MILES: 70,000 ENGINE: 3.5 L V6 About a month ago I noticed that there was a whirring sound coming from under the hood. It sounds very dull and is hard to notice when the car is going under 35 MPH. The whirring will increase and decrease with the speed of the car, so it is very noticeable when driving on the highway as it can be quite loud. I originally though the can could be low on oil, but since adding oil the sound has continued. I have also heard that a fan blade could be bent which would cause the sound, but if the fan is made of plastic, could the blade really bend much without breaking? I know the details are vague, but I am having a difficult time describing the problem, if there is any more specifi information you need, please let me know. I appreciate any feedback I can get. P.S. The exhaust system was rotted and was just replaced today. I hoped that maybe the exhaust was the root of the problem and the replacement would solve my issue, but that is not the case.