04-22-2017,
Any ideas please. My 09 prostar Cummins has developed a very noticeable air sound whenever It reaches 15lb or more of boost and when using the jake. It also sounds like a short burst of air each time the auto trans upshifts. Seems to come from the rear part of the motor but wont do it at all by just reeving the motor while sitting still.I went to a dealer and they put new CAC (I did see the leak) and all new hoses and clamps for the turbo lines. $2800 later I left there and the problem was no better at all! It would make boost in the high 30's before and now 30 is the top and the jake doesnt seem to hold as much. I would be greatful for any help