ZD30 CRD boost problem

Just looking for some heads up from anyone with any ideas;
I was driving back from my folks Saturday night when I noticed my GU common rail ute was lacking power, checked for codes on ScanGauge had nothing, then happened to notice after going back into the gauges I had next to no boost; pulled up as soon as I could popped the bonnet to check for anything obvious, bam found the VNT actuator vacuum line had split, pulled it off cut off the split section hooked it back up and away we went, full boost and full power all the way home. Parked it up for the night, went to use it again roughly 12-14 hours later and it was displaying the same boost as the night before (usually -0.01 to 0 psi at idle, up to 14psi under load, was showing -0.04 at idle up to max 4psi boost) checked the actuator line for any more splits but found nothing, a quick check over showed no split hoses, no split vac lines, etc, also had my brother watch the VNT actuator and under acceleration it was moving. I didn't have time to investigate fully but I will check over everything mechanical that I can this arvo. Just wondering of anyone has had this problem before, it just seems odd that it's the same problem only a different cause, I wouldn't have thought the maybe 10 or 15 ks I did with the actuator not working, and the fact that once the line was repaired everything was fine, would have caused anything else to fail?

I'd check for other vacuum lines for splits/cracks. VNT actuator may not be moving far enough, could be a vacuum leak elsewhere. If one line has cracked/split, others could have too.

whats the condition of the intercooler like? try removing and clean.
be sure its dry before re-fitting
cheap enough to replace all vacuum hoses
Is the IC oily????