Knocking sound

[overshot]

(08-09-2016 )Waterloo Wrote:  Air compressor here too... They can get ugly, might be time to pull the head on it and clean it out... Cummins has a rebuild kit for them when they get sooted up and start knocking like a rod... But, have you done an overhead lately, and how many miles on the truck? The damper needs to be replaced every 500,000 miles as they wear out around then, per Cummins. Oil analysis done lately? How often is the oil changed? All just off of the top of my head...

Overhead was ran in may.
Last sample looked good.
15-18000 on oil changes.
Dampner on the schedule to be changed on the 23rd.
531000 mi/ 11000 hrs on the truck.
I hope it the air compressor