When cold starting the overall impression I'm getting from my M5 is that its rather noisy - perhaps the first 5 minutes or so.
As soon as the temperature rises then noise level drops considerably.
I realize that the idle rpm's are higher when cold, but I'm referring to the noise level when driving. There quite a lot of resonance from the exhaust, and the overall exhaust sound level is quite high. I should mention that the car is completely stock.
I'm not talking about the great sound when the engine is hot and pushed from a little bit to a lot
I read somewhere that the engine management, in order to heat up the cats, makes the car somewhat rough until the temperature is above a certain level.
I'm just wondering if I should start looking for reasons, or if this is just the nature of the car.
Please tell me your experiences.
PS: I have only driven the car in subzero or close (Celsius) temperatures.