CM2350 Turbo Spooling at Idle

[rgunn111]

I've had this issue for about a year, and I've seen mention of it on multiple Facebook conversations but have yet to come up with a solution. My truck often sounds like it's trying to regen at idle or low RPM (under 1000). It's sporadic, but happens several times a day. The engine does not idle up but the turbo does. If I'm stopped and I use the cruise control to set the idle it stops. Turn the cruise off and it starts again. If I let the truck just sit at idle at the end of the day it will stop doing this after about 45 minutes to an hour. The regen (hot exhaust) light does not come on and it is not logging a regen in insite. Instant fuel consumption on the gauge cluster jumps to about 1.6, 1.7mpg. Compared to less than 1mpg at normal idle and over 5mpg during a forced regen.

Does anybody know what might be causing this? I recently read about a possible leaky 7th injector but haven't been able to find the thread again.

Thanks in advance... I've been lurking for over a year.