Turbo problems [Cummins ISX 15]

Hi,

I have a problem with Cummins ISX 15 Turbocharger. When the engine is idling, either cold or hot, after 5 minutes the pressure would rise to 5-9 psi. However, after 10 minutes it drops to 0 psi.


After revving the engine a few times the pressure would come back up. After driving for 30 miles, the pressure drops again. On the road, the problem does not occur, unless I park the truck. Also, if the engine is revved up to a 1000 RPM the pressure drops until I release the throttle, then the pressure comes back up again.


When I’m having the pressure problem the engine sounds and feels different and miles per gallon is lower. It’s most likely to occur when parked, starting the trip or if the truck is loaded heavily. The computer does not show any codes.

Any advice?