Getting a fluttering noise when accellerating under boost. Advice?

[pneumagger]

I'm not sure why, but in the last few days I've been getting this airy fluttering noise when the boost kicks in. I was on the freeway and noticed the noise over the stereo and road (not easy) and thought to myself, "Boy my lifters are ticking BAD and I JUST changed my oil". I turned off the radio and cracked the window to listen and I don't believe the noise was my lifters. It was sort of an airy whistling/ticking/fluttering sound only present when boosting.

I thought maybe boost leak, but all the lines look OK from an inspection. I've only done a visual inspectoin. Plus, boost levels are normal and seems responsive like normal... boost tops out to 12-14psi by 3000rpm. A leak THAT loud would certainly show a pressure/rpm change, right? And the wastegate must be working because I'm not getting any spike over the boost limit.

Leaking BOV? There is a "fluttering" periodicity to the noise - maybe a worn out BOV (OEM from 1992)?
Could this be compressor surge? ... (on a "low mile" big 16g only pushing ~13psi ?!?)
Maybe I have a ton of oil in my intercooler (factory SMIC)?

1992 TSI AWD, 6bolt/4bolt, Buschur Big 16g with Upper I/C pipe.
I had JUST changed my oil last week (Mobile 1 syn 10w-30 and purolator filter), installed the cat, passed echeck, then reinstalled the test-pipe.
Went on a 5 hour road trip that same day too - nothing out of the ordinary.

[SvenDiesel]

I used to have flutter up the wazoo. I have a Forge RS Bov and I couldnt half pedal my car to accelerate on the highway.

I used to have tons of boost leaks, I fixed 98% of them. There was one remaining boost leak I had, which was from where my alcohol nozzle is tapped into my IC pipe. I tightened the nozzle up, drove the car, I can now 1/4 and half throttle my car to accelerate. Definitely double check all of your potential boost leak areas.

[GRAVEDIGGER]

Sounds like a bad bov. Usually when you get an uncontrollable flutter like you are explaining it's an issue with the bov. You need to do a boost leak test though for sure. It might even point you right to the bov.

[erald01]

could be a turbo surge.

[JustA4DR]

Check the coupling from the bottom of the turbo to the lowe ic pipe, inspect for any tears or penetrating damage. Awhile back mine blew up like a baloon on the dyno and split vertically around the back of the silicone hose so it was visually hidden and it also had a flutter but would vacuum down off boost around 5-10psi....good luck on identifying the problem bro.

[teddygram]

Do a boost leak test and get back to us. I believe it is your BOV. Is your bov crushed? If not try giving it a little smash, or just buy a new one.

Grant

[Demon Eclipse]

Sounds like it could be compressor surge.... Does it feel like you loose any power? if its the bov the diaphragm could be bad in it..