Hi, I'm new to this group. I have a '99 SVT with about 43K miles. When it gets cold (which starts in September in Rochester, NY

) I get this very annoying engine noise that sounds like a ghost moaning. It is very loud, both inside and outside the car, and it goes away after about 10-15 minutes of driving and the engine is warmed up. Has anyone else encountered this?
Thanks for any tips.
Mike