Air Pump Check Valve ?
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Joined: Apr 2008
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Air Pump Check Valve ? Are these valves "directional" (one way)?
I had the rubber hose connecting the check valve to the pipe that wraps around the front of the motor off to swap a ICM (just for easier access) and when I started car with it off I heard/felt a "popping" sound following engine cyl rhythm coming from the hose opening. It was exhaust coming out.
Thought only air "from" air pump goes into valve...not exhaust coming out of it
I also see STFT going from 0 at idle to 3-7 as RPM increase on that bank, DS. so wondering if check valve is bad causing exhaust leak
The valve is 22 year old original
It also could be the valve on other side as they both connect to the "U" shaped tube on front of motor
I had the rubber hose connecting the check valve to the pipe that wraps around the front of the motor off to swap a ICM (just for easier access) and when I started car with it off I heard/felt a "popping" sound following engine cyl rhythm coming from the hose opening. It was exhaust coming out.
Thought only air "from" air pump goes into valve...not exhaust coming out of it
I also see STFT going from 0 at idle to 3-7 as RPM increase on that bank, DS. so wondering if check valve is bad causing exhaust leak
The valve is 22 year old original
It also could be the valve on other side as they both connect to the "U" shaped tube on front of motor
I had a similar problem. I had hooked up all my AIR stuff just for emission inspection (already disabled in tune) and left the chopped U-shaped pipe just hanging under the engine. Then it took me a while to track down a faint puffing sound, which turned out to be exhaust leaking out of that tube.
I assumed it to be the same thing you did, old check valves leaking. I've since ditched most the the metal line and replaced it with hose just so there's no leaks, but I imagine if the AIR system was actually working on mine with the pump pushing air that there wouldn't be an issue.
I assumed it to be the same thing you did, old check valves leaking. I've since ditched most the the metal line and replaced it with hose just so there's no leaks, but I imagine if the AIR system was actually working on mine with the pump pushing air that there wouldn't be an issue.
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I just pulled the hose off each check valve. The sound I hear is air being sucked "in" to exhaust, not exhaust "pushing" air out as I initially thought. I held my thumb over valve and it was definitely sucking in.
The air pump is electronically (PCM & relay) disabled so it is not "pushing" any air into the check valves as it would if the air pump system was enabled.
My thought is I have a indirect vacuum leak pre 02's as even when with the check valve hoses hooked up to the unmolested U shaped metal tube on front of motor which air pump is connected...that may not be air tight.
The "in" side of each check valve where rubber hose connects to them the hoses are not heat stressed which if so would suggest exhaust is pumping "out" of them towards the air pump.
Not sure if the valves open from suction from the exhaust (headers) or only open if air is "pushed" in from air pump
The air pump is electronically (PCM & relay) disabled so it is not "pushing" any air into the check valves as it would if the air pump system was enabled.
My thought is I have a indirect vacuum leak pre 02's as even when with the check valve hoses hooked up to the unmolested U shaped metal tube on front of motor which air pump is connected...that may not be air tight.
The "in" side of each check valve where rubber hose connects to them the hoses are not heat stressed which if so would suggest exhaust is pumping "out" of them towards the air pump.
Not sure if the valves open from suction from the exhaust (headers) or only open if air is "pushed" in from air pump
