Ammo, I sent you a test version of the P47D25. I never could hear what you are, but I looked into the way I mixed it and I think I can see what might be happening.
What I have done here is shorten the idle sound so that it reinforces the engine sound. The result is that the engine idle in AH is also reinforced. The sound in the SPCS pack has had a lot of 'mud' removed, but the engine sounds I have sent you are a little different. The ENG sound is just as I described with idle set to -12db. The ENG-2 sound has the engine idle set to -6db. Both have a hard limit of -1.5db, but I would probably set the limit to -3db if I did the same thing in the full version. I think it may even be a good idea to turn idle up to -3db, but before I do that I want to know if what you were hearing has disappeared.