andrewtapin

I have this severely loud hissing noise coming from the back of my engine on the right side(Passenger). It's only present when my engines in vacuum wont hiss when in boost.

I checked most vacuum hoses around that area with no success but engine was to hot to feel lower... is there any pumps/pcv or check valves back there ?

Thanks!

nanayaw6

The PCV hose on that side slides onto a nipple on the valve cover toward the rear.
Assuming your PCV system is still stock, the opposite end of that hose connects into a T fitting that plugs into the bottom of the TB.

andrewtapin

Hey nope no issue there... Today I even went the extra mile to take my throttle body off to see underneath. It almost sounds like a power steering whine and now I also have the Map sensor check engine code presumably because of vac leak ?

Any more help please this high pitch whining is driving me insane!

Roverron

Check bypass flap gasket. Was s/c recently removed.

andrewtapin

Ooo I like the way you think! I overlooked that. I'll check that and report back! Thanks alot