Vacuum leak question?
01-31-2008, 05:35 PM
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Vacuum leak question? Just finished installing a fast intake on my 98 vette. My question is what does a vacuum leak sound like? The car idles perfect, doesn't miss, and has a smooth idle. But when you raise the rpm's slightly there's a small whistling sound. I've got a vararam also but I'm not quite sure if that's what I'm hearing. The car doesn't lack any power, no codes, etc. Could the whistling sound be a small vacuum leak or am I just paranoid? Any ideas?
01-31-2008, 05:39 PM
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Might just be that you have alot more air comming in mine sound like a vaccume cleener now haha, but one way to check it spray some starter fluid around the intake and if it brings the rpm's up then you have a leak, this is somthing I might try but its probly not the best way haha.
01-31-2008, 05:46 PM
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yeah, starter fluid trick works well.
Inspect all your PCV hoses and check your PCV at the back of the DS valve cover. If no leaks you should be fine. Take a look at your blender valve near the PCM also.
Inspect all your PCV hoses and check your PCV at the back of the DS valve cover. If no leaks you should be fine. Take a look at your blender valve near the PCM also.
01-31-2008, 05:59 PM
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Just spayed starter fluid near all the pcv hoses and around the tb and around the base of the intake and no change in the idle. Still runs fine. Where is the blender valve located? Is this the small vacuum line that plugs into the rear of the intake on the pass. side?
01-31-2008, 06:23 PM
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If a real vacuum leak acts different, then your noise is probably
not a vacuum leak. Might be the air at the throttle blade (sharp
edge, makes whistle?) and the elimination of factory "silencer"
features (which is what makes the stock F-body lid, and maybe
the 'vette stock intake, suck).
A small vacuum leak will be a soft hiss, at most.
Might try a listen with the air cleaner off so you can tell it it's
in the throat.
not a vacuum leak. Might be the air at the throttle blade (sharp
edge, makes whistle?) and the elimination of factory "silencer"
features (which is what makes the stock F-body lid, and maybe
the 'vette stock intake, suck).
A small vacuum leak will be a soft hiss, at most.
Might try a listen with the air cleaner off so you can tell it it's
in the throat.
