Not sure if I entirely understood you Question.
Of course, alligning a new Value to the Variable EngineVolume does in no way automaticly alter the Volume of the engines soundchannel. Instead you need to set the Volume using the Commands "ChannelVolume" every time you want to alter the Volume etc.
Always use the PlaySound Command with a Return Value:
(example)
snd_handle=LoadSound("ding.wav")
LoopSound snd_handle
...
channel=PlaySound(snd_handle)
ChannelVolume channel, 0.5
ChannelPitch channel, 22050
Of course, alligning a new Value to the Variable EngineVolume does in no way automaticly alter the Volume of the engines soundchannel. Instead you need to set the Volume using the Commands "ChannelVolume" every time you want to alter the Volume etc.
Always use the PlaySound Command with a Return Value:
(example)
snd_handle=LoadSound("ding.wav")
LoopSound snd_handle
...
channel=PlaySound(snd_handle)
ChannelVolume channel, 0.5
ChannelPitch channel, 22050