Air compressor ticking

[Chamberpains]

Possible head problem, maybe a ticking unloader valve, could be an air leak between the air gov and compressor, could be the little 4" air line from the compressor to the intake is split. Or if you haven't had the truck long it could be just the nature of the beast and you just now noticed it. Cm870 and cm871's are very well known to rattle or tick while building air and stop once the governor pops off. I'd check all the above 1st. If that all checks out and its only while the compressor is building air, I'd say its the nature of the beast. One final thing i can think of you can check and I've seen guys on other forums report it solving their ticking is checking the cam gear timing with the proper timing wedges. Checking mine never solved the rattle/ticking but it never hurts to know for sure if a cam gear has slipped.