00 E39 M5 Question on engine sound
The other day when a neighbor was standing next to it he commented that my car sounded like a deisel engine as it was idling. He actually thought it was a deisel powered car. He knows nothing of BMW of course :-). But ya I'd have to agree with him it does sound like a deisel engine at idle. This is not exhaust noise. Behind the car at the exhaust it sounds like a normal M5. It doesn't matter if the engine is hot, cold, been driving a while or just started. It sounds like a deisel when standing in front or next to the front of the car.
I've not stood next to another E39 M5 in a very very long time so I have nothing to compare. Next time I have the car out I'd be willing to make an MP3 if any here think it would be worthwhile to determine if there is an issue or if it is normal.