Another Cruze issue. I have a 2011 Chevy Cruze that I purchased certified from a dealer in 2014. It now has 72k miles on it. All of a sudden I noticed that the car is louder when I'm accelerating - it's a regular engine noise, just louder. It gets lower/quieter when I take my foot off the gas, and higher/louder when I accelerate. It is quiet on neutral. It also doesn't seem to matter if I'm in automatic mode or manual, and doesn't change volume or pitch when the car changes gears. What the heck could this be? It's like a low "hmmmmmmmmm". The power doesn't seem to be altered, and otherwise the car drives fine, but it's incredibly annoying. I've already had massive transmission issues with this vehicle and had it completely overhauled at the dealer, so I'm fairly confident that it's not the transmission. Any suggestions?