2011 workstar thumping noise in intake

ive got a 2011 workstar and its making a thumping noise that varies with engine speed. We just replaced the throttle valve as it was stuck. Did a cylinder contribution test and they were all within 2-3 percent. Also did an injector buzz test with no faults no codes in the engine computer after throttle valve replacement.

 

Also DPF system is clean and the media is intact

 

The engine has no performance issues no stalling no missing just the thumping in the intake and it varies with rpm. I will look into the air compressor tomorrow and let you know.

 

We checked the air compressor today disconnected it from the intake piping and still she thumps. The department wanted to use the vehicle so i didnt get any fiagnosis in today other than that. But im thinking it is going to be a flat lifter or a bent pushrod

 

But yes the sound is new according to the operator but who knows anyway because with the hood down at idle you dont notice it and while you are driving you cant hear it unless you are looking for it. So i dont know if the noise is actually "new"