AutoMD ... 10/28/2013
2004 Pontiac Bonneville SE 6 Cyl 3.8L
What is making my car engine rattle and sound like a helicopter when in idle and when accelerating?
Just recently (when the weather turned cold) I have had these problems with my Pontiac Bonneville:
A. Engine rattling, it could come from a loosing catalytic converter shield or a broken motor mount. Use a two feet garden hose as a makeshift mechanic stethoscope, and locate it where the noise comes from.