00NogaroS4

My car has just started making a low pitched whhooo sound on acceleration (no its not turbo spool). Sounds like it is coming from under the dash-HMMM. It also happens more when its cooler than warmer - but not all the time. As reference, my car is piggy stage 3 (full) with tweaked GIAC X. I was thinking it might be a DV leak but it tests fine when I use my finger to hold the diaphram (I don't have a mityvac)? Comments? Recently I had a loose fitting on the line from the drivers side turbo inlet to the MBC which caused some boost spiking. Noise started just after that. This leads me to question the wastegate. The turbos are about a year old and the car runs about 20psi at redline (very conservative I know) so I don't think its a turbo. Interestingly, my buddy has the same noise on his stock 01S4. Any thoughts? Thanks all.

quickaudi:STFA

pressure test time, just in case.

pane2k

spikes and now you noticed it? I know that happends with me somettimes.

slava

hi, i have same noise, and i noticed it after i put on apr chip on my 01s4. also i think i lost power on my stock mode

Salscal

but not gone. Is the sound kind of a honking sound at part throttle? Very tough to describe the noise it makes. Let me know if you come up with something.

AussieA6_2.7T

Changed car from 4.2 to A6 2.7. Had a very similar problem after installing APR Stage 1. Ended up being diverter valves plus throttle body pipe was split (failed with the extra boost. APR showed up other faults which have been fixed so all good now.