I was in a tank yesterday and after starting the engine if I stayed still the engine sound didn't play, there was no idle. The engine sound didn't kick in until I was doing at least 10-15mph. This happened in every GV I tried.
I went to fly and pretty much the same again, if after starting the engine I left my throttle to 0 no enigne sound was played, I had to increase throttle to around 25% before the engine came in.Again this was for every aircraft.
I have a sound pack which I removed, and yet even with defaults it's doing the same thing, Online, Offline and in the Beta Test arena.
(I could well have been having this issue for some time, I remember a few weeks ago an M18 I was crawling along in, wasn't playing any sound until I got up to speed.)