I've got 12k kms on my EBoost, about 7k miles also. I've noticed that under light acceleration both empty and loaded that the turbos will sound like they're building up slight boost then blow off on the waste gate. I think its a normal procedure as the throttle pressure isn't requiring full spooling of the turbos to create full power, but only a little at a time to sustain the current speed. Not sure if we're experiencing the same sound/condition... Under hard acceleration does it act normal?