Since there's so many knowledgeable BMW specialists on this forum, I thought I would post this rather specific question here. My wife's '97 328iC has the factory dual exhaust. While at the bus stop waiting for my kids to come home from school, I got under the hood and listened to the A/C compressor, which seems to make a lot of clicking type noises. Prolly on the way out. That's another story.
Anyway, on walking to the back of the car, for some reason I put my hand down near the dual outlets from the muffler. I was surprised to find exhaust exiting from only one. I know that there is a diverter valve in the system somewhere. The engine was hot and idling. Does the diverter open after a warm-up period? Or is it RPM/vacuum dependent? Should a fully-warmed engine be using both outlets at idle?
What is the normal sequence of operation for the exhaust diverter?
