Since 1.65 (no idea if it happened before) it happens often that if a vehicle gets destroyed near a player the engine sound of the vehicle stays.
If it happens it doesn't matter to which position the player moves he can hear the engine sound (even though the vehicle is destroyed) at the same spot, means also the same distance.
This is killing immersion quite a lot because you always think that there is a vehicle beside you but it is the sound of the destroyed vehicle engine which you can still hear.
Once the vehicle gets deleted the sound goes away.
The bug is also still there in 1.67 DEV version. Just did some testing with the new 1.67 64 Bit version yesterday and had the problem again.