i have a 2.0t dsgand soemtimes instead of the turbo spooling i get a constant "chhhhhhhhhhhchhh" sound. i give it more gas and the sound goes away and the turbo then starts spooling. anything wrong about this?

 

What year is the car? Do you have any mods or a chip tune? In what gear(s) and RPM range(s) is this problem occurring?

 

2007 audi a3 2.0t dsg. i have revo stage 1, forge dv, milltek catback, stock downpipe. sound occured without mods as well.sound happensin all gears in moderate acceleration between 2800-3200rpm. does not occur when hard on gas - sound dissapears and turbo spools. any ideas?

 

Hmm... I'm stumped. I haven't noticed this sound on my car (2007 2.0T DSG - stock). Dumb question - is the sound coming from the engine bay or perhaps a bit further back? Possibly a loose exhaust hanger?

 

haha me too i have been troubled for a long time and couldnt figure out what it is. it seems like its coming out from behind the glove box /under the passenger sideat the front.

 

Well this is really a shot in the dark, but perhaps it is the infamous fuel line rattle. I don't think this was corrected until mid-2007. If you can get under the car to look, your fuel lines run under the passenger side floorboard -- if your's already has the fix, there should be some rubber dampers on them to isolate the vibration. It could be that at a certain speed/RPM your car is producing just the right 'frequency' of vibration to make them rattle... or maybe you just can't hear it over the engine once the turbo spools up and your RPMs are higher.

I believe there is an exhaust hanger right about where the firewall meets the floorboard too, you could probably check that while you're under there. I know there was one aftermarket exhaust (can't remember the brand) that a few people here had and their exhaust mount/hanger failed.

Otherwise, your turbo/downpipe is between the backside of the engine and the firewall... maybe something else is loose and rattling against it. It's been a while since I've had a good look back there, so I can't tell you off the top of my head what may be in that area that could be loose.

EDIT: One more quick question. Do you have a boost gauge? If so, how much boost is your car making? Stock it should spike ~15 PSI and hold at ~10 PSI, not sure about Revo but most of the chip tunes should be in the neighborhood of ~23 PSI spike and ~15-16 PSI steady.

 

thanks bamf.
your input is appreciated. i'll take a look and see wats up.

 

You may have a torn diapharm on your bypass valve. Pretty comon, theres even a tech bullitin for it. Its also on the passenger side near the firewall. Also check your pcv valve assembly for leaks or cracks.

 

hmmm not the dv for sure coz i jus upgraded to forge dv

 

This is a common problem that most people don't even recognize. I have the one-way check valve that I use all of the time, except I replaced it with the OEM hose prior to my 35k check up. I left it for a while and noticed that I couldn't get the boost to spike over 15psi. I replaced it with the check valve again and I'm peaking at 23psi and holding 19ish, depending on the gear and rpm. It could very well be your problem. Too bad you don't have a boost gauge.



Cheers!