jprice@CPS

Original thread (with recorded noise): <a href="https://forums.audiworld.com/a4/msgs/2604900.phtml">https://forums.audiworld.com/a4/msgs/2604900.phtml</a>

Today when I got home from work, I could hear the groan groaning away. I decided to try and narrow it down a little.

I pulled off the inlet into the airbox, and noticed immediately the groan was loud coming from the intake (could hear through airbox).

First I clamped the vac line that goes to the BPV... noise didn't stop. Then I clamped some of the other air and vac lines, no change. I disconnected the secondary air from the airbox, no change. Then I unplugged the PCV hose that goes to the "puck valve" on the inlet hose. Suddenly the airbox went quiet. With the stethascope, I definetly could hear the groan coming from the pipe that goes to the puck valve from the PCV system. I played aroud with plugging up and then unplugging that pipe, and the noise went away.

Huh.. I guess I should pressure test (very small amount of pressure) the PCV system.

Maybe my puck valve is bad and the PCV system is getting pressure and or vacuum it wasn't designed to withstand?

TristanP

Interesting - keep us updated

shawfm

I have planned on just replacing everything on the intake mani side.

jprice@CPS

Frustrating. It's definetly coming from PCV.

shawfm

I think October 7,8, or 9 is when I may get around to it.

jprice@CPS

I plan on spending some time this weekend narrowing it down further.. I'll follow up.