I decided to check for boost leaks today since my vac is off and im blowing a bit of black smoke when at wot, and i noticed air comming out of my bov when at idle. I have a 1g bov, unmodified, i felt a small bit of air at idle, then a whole lot of air when the engine is revved. This isnt supposed to happen...is it? It seems to me like a substantial place for boost to be leaking. Thanks for any ideas
Leaky BOV
FlaToUt-GST
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I decided to check for boost leaks today since my vac is off and im blowing a bit of black smoke when at wot, and i noticed air comming out of my bov when at idle. I have a 1g bov, unmodified, i felt a small bit of air at idle, then a whole lot of air when the engine is revved. This isnt supposed to happen...is it? It seems to me like a substantial place for boost to be leaking. Thanks for any ideas
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i take it you are venting into the atmosphere. vent that sucka back into the intake
mine leaked when at idle too
mine leaked when at idle too
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1G BOV's are open any time there is a negative 7.7 psi pressure difference between the upper and lower chambers of the BOV. 18 in hg is -8.84 psi, guess what a 1G BOV is doing at idle.
Older 1G BOV's can leak boost around the shaft to the valve from the lower chamber thats ported to boost pressure. The valve can be sealed and still leak from the port in the base of the BOV up into the lower chamber past the shaft and out. I suspect there's a seal in there that wears out but I haven't disected one to check.
Steve
Older 1G BOV's can leak boost around the shaft to the valve from the lower chamber thats ported to boost pressure. The valve can be sealed and still leak from the port in the base of the BOV up into the lower chamber past the shaft and out. I suspect there's a seal in there that wears out but I haven't disected one to check.
Steve
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humm
Its a good thing. Running rich is much better than running lean.
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Cool then i dont need a new bov for this friday (track) i still hate looking up and seeing tht 15in hg vac. Owell ill do an actual pressure test today and see what happens
Thanks for the help!
Thanks for the help!
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I was thinking of crushing it, but im afraid of ruining it if i screw up. ANother thing i was thinking about...the bov is open at idle (18 inhg..or 15 in my case), however, when i rev the engine vac jumps to 0 in hg, yet the bov is still open since a ton of air comes out of it...is the vac change just too sudden? It seems like a bit of a waste for intake air to just circulate back through because the bov is open...
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I defer to our mods but I caught that in your earlier posting and suspect your BOV is leaking. Like I said, my does around the shaft. Since I'm not venting to ATM it makes my turbo work a little harder but dosen't mess up my fuel metering because it's rerouted back after the MAS. If your venting that's counted air that's leaking under boost and uncounted air leaking in under vac.
Steve
Steve
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64 Posts
I was only venting for a little while..the hose popped off one day and it ran fine and sounded sweet so i left it. It's back on now though. I should have time to pressurize the intake system today so i will see if it leaks at all. Uh...another question, not about the bov ...i know my vac may be low due to timing, and i know the teeth are supposed to point directly at each other (not like they could interlock)...mine point at each other sometimes, but when the notches on the timing gears are at about 1 o' clock the teeth look as if they could interlock...am i off a tooth? thnx!
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