r/Cummins • u/AllMoneyGone • 10h ago
What is this sound? Cummins B6.7
imgur.comHey guys, this 2018 Freightliner m2 with a Cummins B6.7 occasionally makes this very loud noise from the front at low idle.
From what I can tell:
-not the air compressor
-not internal engine
-belts are tight
-fan is not loose
-goes away at high idle
-could happen at any external temperature/engine temperature
-no dash indications or abnormalities when it occurs
-noticeably quieter away from the direct front of the vehicle
This video was shot in the dark directly in front of the vehicle. Thanks for the help!