: Overpressurize relief valve boot

04-23-09, 12:11 PM
New to the site, I have a 2005 deville with 106,000 mi, perfect timing for gm to let stuff fall to pieces right out of warranty.

I believe the piece is part of the "overpressurize relief valve" or "pressure relief pipe" or even called the "pcv pipe" in some of the forums. It is the plastic pipe that runs inside the center of the intake manifold (behind the power steering pump) opposite side of the throttle body/air intake. I called the stealership and they said they can sell me the whole intake manifold but that otherwise that piece was "not needed?". anyhow, the boot that connects the plastic tube with the part inside the manifold is cracked in half. Its just a 90 degree rubber elbow boot. Does anyone know the correct term for this piece so i can have another go at the dealer? I have a feeling i am going to have to remove the intake and do the pelum,penum whatever it is as well.

04-23-09, 12:57 PM
If the 2005 is anything like the 2002, the overpressure relief is a spring loaded mushroom valve in the center of the intake manifold at the p/s pump end. Once in a blue moon one will hang up after a forced downshift and possible backfire. Not common.

The rubber elbow - about 1/2" pipe ? - can be found at any large parts store in the "Help!" blister pack section. That's the PCV vacuum connector which comes from the right (rear) cam cover and snakes into the same area as the overpressure valve. Even if the plastic pipe is broken you can either sleeve it with a proper sized piece of vacuum line (same parts store) or run the entire thing with rubber vacuum line.

The hand in the diagram is lifting in the overpressure valve recess.....#2 is the clamp for the rubber plenum connector boot.

BTW----- Hello ! and Welcome Aboard........