strange clicking noise in cummins isx
Hello, recently I bought a Volvo 2008 truck with Cummins ISX 400ST engine. When letting go of accelerator there is a strange rapidly clicking noise from the engine. It is not very loud and I don't know is it normal? Newer had this engine before. The truck is a old Swift truck. When I accelerate the is no noise at all, as well on idle or PTO. There is also a switch for an engine brake with three positions, but it appears to be working on position 1: whereas 2 and 3 is the same braking, my old truck was different. I also don't know is it normal.
Is this a good question?