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PassatWorld Staff
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Discussion Starter #1
Woo is me. :sad:

I have a "woo." It only happens under boost. It's a noise almost identical to a bosun's whistle, but it's not as piercing and kind of friendly so it's a "woo." Oh - and it's totally boost-dependent, not RPM - same whistle at same level(s) of boost regardless of gear.

The last time I had a woo, it was the cracked CAT converter at the turbo outlet flange. It woo'd once a week or so, then I took a road trip and in Denver, it started wooing loud everytime accelerating out of a toll booth. The very last booth, it went wooo-fip!-BWAAAAAAHHHHHH :shock: as the CAT pipe popped out of the flange. :lol:

But that is not the case this time. I have had the CAT off twice to check, and replaced a bad gasket, and that's just not it. Last night, I replaced all the 2" silicone FMIC couplings with much-better-fitting 3" ones. That wasn't it, either.

This woo started in late August. At first, it would only happen once in awhile. Mid-September, it started happening at 10+ psi boost. About a week ago, it started kicking in at 7 psi. Two days ago it started kicking in at 4 psi, and if you stay on it, by the time you hit 10 psi the woo stops. In that 4-to-10 psi range, you can play a tune with your right foot - the pitch changes with boost. Funny, though, it goes low-high-low over that 4-10 spread. It doesn't start low and then just keep getting higher. And it's a fairly discreet two tones, just like a bosun's whistle. Low-high-low.

I've double-checked the vacuum lines - everything is tight and holding.

Please help me fix my woo - my next best guesstimate is that it's one of those plastic one-way valves in the vac plumbing. I don't have an opportunity to troubleshoot. I'm at work this morning and leave at 11:00 for the Minnesota GTG. But I want to stop by the dealer on the way out of town and pick up whatever might be likely to go bad, so I can easily replace it on-the-road if necessary.

Woo is me...
 

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lol. My supercharged Honda would woo (or whistle pretty loudly) around 3/4 throttle. But that's Heimholtz resonator style, over the bypass I believe, and is pretty normal. Woo's shouldn't develop over time. :)
 

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PassatWorld Staff
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Discussion Starter #5
D*mn. I wish I could have posted this earlier. It's time to leave... Minneapolis here I come! - so I'll just grab a couple of check valves and hope for the best. If all else fails I have duct tape... :)

Stupid woo. :p
 

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You've checked the entire boost track? DV? Intake? Exh path?

Woo is you! :lol:
 

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PassatWorld Staff
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12,267 Posts
Discussion Starter #7
The woo is gone.

It disappeared on my Minnesota trip (what a fabulous drive and a GREAT GTG! - the Minnesota Passat Group rocks!), and it hasn't come back.

I hate these things that are impossible to diagnose until something FAILS...
 
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