engine noise similar to blowout valve
May 10, 2005 | 01:13 PM
#1
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From: Lake Mary, FL
engine noise similar to blowout valve
I have been experiencing a noise from my engine similar to a blowout valve...well more like a deep belch when i come off of the accel. I have traced the source of the noise to the back left of my 3vz-e, its a black rectangle with a valve coming out of it, it appears to have 4 holes for screws but all of them are missing..i was wondering if anyone had any clue as to what the purpose od this valve was...I cant seem to find an engine diagram anywhere to find out for myself...
Last edited by GA95Runner; May 10, 2005 at 01:16 PM.
May 10, 2005 | 01:19 PM
#2
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From: Raleigh NC
nothing other than the exhaust at the rear of the truck should be making any noise especially in response to release of the throttle, a picture would sure help or a more accurate description of its location.
and its a blow-off valve, not blow-out
and its a blow-off valve, not blow-out
May 10, 2005 | 01:39 PM
#3
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From: 100 miles offshore as much as possible, & Springfield Oregon USA
This thing?
May 10, 2005 | 02:46 PM
#4
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From: Raleigh NC
ive taken literally every square inch of my truck apart and put it back together and i have no clue what that picture is of 
May 10, 2005 | 02:52 PM
#5
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From: Wenatchee, WA
That is the air suction reed valve. It's an emissions control device designed to reduce hydrocarbon emissions. It uses the negative pressure pulses in the exahust system to draw in filtered fresh air which burn any fuel that remains.
May 10, 2005 | 03:07 PM
#6
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From: 100 miles offshore as much as possible, & Springfield Oregon USA
So, if THAT's what's making his noise, then could it be working properly - hitting overly-hot-overly-rich unburnt gasses with cold air, causing combustion? Or maybe it's just shot and making noise. Or something...
May 10, 2005 | 03:29 PM
#7
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From: Wenatchee, WA
If the reed valve inside the mystery box fails then a bubbling noise will be heard coming from the airbox. If the screws are missing then I'm going to bet the valve has failed due to inadvertent self-disassembly. I've never disassembled one so I can't say for sure if it can be reassembled. Junk yard reed valves are cheap and I believe they are similar for all 88-95 pickup/4runners with the 3.0. I highly suggest repairing the reed valve system. Toyota designed their emissions controls system around everything functioning. I do not have any solid data on what a malfunctioning reed valve will do to your fuel trim adjustments. I can make an educated guess and say that the O2S would see less oxygen in the exhaust and the computer would compensate by leaning out the fuel trim.
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