Regal CXL 2.0 Turbo engine growling / droning noise
I have a 2011 Regal Turbo T07 Russelsheim version that I love, except for one problem. The car makes a growling / droning noise that comes from the engine compartment, on the passenger side, mainly on moderate acceleration and while cruising at 40 MPH after reaching top gear. At first I thought it was the sound of the engine lugging because it sounds a lot like that. But after paying more attention, I realized that the noise was happening at other times. For instance, when driving slowly around a parking lot with light throttle. It's a very annoying sound that’s embarrassing if other people are around and hear it.
My dealer has attempted to fix it several times but no luck so far. This is what they’ve done to try to fix this:
1. Isolated and insulated the AC lines to keep them from vibrating against the body.
2. Replaced the serpentine belt and belt tensioner
3. Replaced balance shaft chains and worn shoes
Does anyone else have any experience with this noise coming from their car? Has anyone had any luck at fixing it? Does anyone know the cause of the noise?