Car sounds like a diesel engine but it comes and goes on 2006 Dodge Stratus

I have a 2006 dodge stratus and its occasionally making a humming which turns into a helicopter sound while driving. But when I am at a light or in a drive through where it is out of gear or sitting it will click over and make a Loud diesel engine sound. I am thinking its my AC so I turn off the AC and it goes away but only for alittle bit. Then it comes back, just not as loud. My daughter thinks its the air filter "something inside of it" even the "DODGE dealership" was baffeled. I dropped it off at the dealership but I was wondering if anyone had any ideas?

by in Gloucester, VA on July 31, 2010
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1 answer
ANSWER by , January 21, 2013
did you ever get this figured out? i have the same issue and cant figure it out. i work on my own cars and have done everything i can except pull the head and check the pistons.