Air Intake Vacuum Hose?

[GrumpierGrunt]

1999 Ford Ranger 3.0 FFV 2WD Auto Standard Cab 141k

Hi all, I started getting this very strange noise upon startup and deceleration. I would call it a resonance, much like blowing air across the rim of a glass bottle. I checked all my fluids and everything seemed normal with the operation of the vehicle. I drove it like this for a bit but the sound got worse, eventually I started to experience rough idle, lagging throttle response and the engine stalling out. I continued to investigate and determined that the sound was coming from the air intake hose, as the sound quit when I removed the air intake.

Eventually, I found air being blown out of the intake in the hole immediately to the right of the temperature sensor, it seems that the plastic coupler wasn't getting a tight fit in the air intake and it was blowing by the coupler. The coupler connects the air intake to via a piece of rubber hose to a separate hose coming from the passenger side of the engine. Can anyone enlighten me as to what this hose is for? It seems like its a breather/pcv related?

Truck runs great without the hose attached, which I don't full understand either, is there a restriction somehwhere?

Also, what is the fix here? I was looking at new intakes, but the coupler doesn't seem to be included and I would imagine it must be press fitted. I considered getting a silicon sealant to permanently seal the coupler to the intake, as it seems the rubber has softened up over time and released its grip of the coupler, thus allowing air to blow out of the intake. Leading to the sound and poor running.

 

[SenorNoob]

RTV is what I would do there.

 

[superj]

me too

 

[pjtoledo]

that's the inlet side of the Positive Crankcase Ventilation system. clean/fresh air moves from the big rubber tube to the pass side valve cover,
then down into the crankcase.
since the small hose is after the Mass Airflow Sensor a leak there allows unmetered air into the engine, so it won't run properly.
air should not come out there. if it does that means the PCV valve/system is clogged.
the PCV valve is in the rear of the driver side valve cover. the hose attached to it is a major PITA and will be hard & brittle.