sounds like a air compressor.

[wildwood]

My truck is a year 2000 model Got a good question for you all. why does my truck sound like a air compressor? you know the thump thump noise coming from the intake. it just started doing it last week. I did a valve check yesterday made no change to the sound. the only thing i can think of is a bad valve. what do you think.

 

[joefarmer]

Dropped a seat, bent pushrod, broken valve spring, hole in piston, etc.

 

[wildwood]

is there a easy way to check it. truck runs fine. just hear the noise out of the air filter.

 

[Rollin Coal]

my truck has always made that noise, 30,000 miles now.

 

[wildwood]

mine just started. hope fuly its not something serious that i have to tear down the motor.

 

[02fuelhog]

Mine started that noise after i removed the stock air filter and box, about 70k ago.

 

[Rollin Coal]

Mine started that noise after i removed the stock air filter and box, about 70k ago.

yeah defiantly cant be heard through the stock air boxes baffles

 

[grncummins]

It is completely normal dont worry about it every cummins ever built does it.