Im new to yotas and a week ago i got my new truck running. I bought it w/ a blown rod and swapped out the longblock, so i never heard it run normal beforehand. anyway when i am at idle or slow roll i heard a intermitant bogging sound, it sounds like something is turning on and off. The motor has a "rv" cam. anyone have a similar sound, and or know what it could be?

 

 

the last 'bogging' sound I heard was from tires hitting mud and that little 'squishy' sound the tires make.

but if the noise is coming from the intake, it may be resonance from the intake you're hearing. As the engine rev's up, the resonance will oscillate from even to odd harmonics and back again, and will change the tone you hear.

If you're not experiencing any change in engine performance when the sounds change, I'd chalk it up to 'natural noise'.