I had some work done on my 2007 997.1tt tip car (engine out to fix coolant leak). I also had the dealership install my EP1 exhaust at the same time. Anyways long story short there is now a strange noise when the turbos spool up. If you are in the car it almost sounds like one of the "party spinning clicking toys", I would describe it as a ratcheting sound (to me it sounds metallic almost). It happens as the car is quickly going from low boost to high boost. The noise did not really persist if I maintain full boost though, it's almost like there it is just when the turbo starts winding up. Speed does not really matter, I can make the issue happen at lower speeds provided I push the boost high quickly. There are no mods to the car other than the exhaust (no tune). Any ideas as to what this might be? I took the car straight back to the dealership but I wanted some second opinions. I took some video of the issue, it's not the best quality and you kind of need to crank the volume to 11 to hear it but maybe someone is familiar w/ this issue and can chime in. BTW, it didn't really seam like there was a loss in boost either (but it has been a while since I have driven the car so maybe I am not the best judge).

http://www.youtube.com/watch?v=W-q2ux5FMRA&feature=youtu.be


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It almost sounds normal to me, but it's difficult from the video to get a sense of all the different sounds going on (road noise, etc). I think I hear what you're talking about, the Europipe exhaust note is a bit raspier than the factory - I'm hearing some of that. But what you're describing as a ratcheting sound is more than likely a boost leak at the throttle body/plenum area. Could a 'flapping' sound also describe it to you?

 

My guess it's a boost leak. It's not uncommon when installing a new exhaust to accidentally knock a hose loose to the IC.

 

Will a boost leak throw a CEL? Cause unless it does, how do you really know?

 

No, none specific for a boost leak. If there are no fault codes, then diagnose by symptoms/history. First thing to do is check boost hoses.

 

Couldn't really hear any ratcheting or clicking and clip was so short and contaminated with other sounds but if i was to make anything out of it, it as as others say, boost leakage somewhere. Did you take the I/C's off or any hoses when installing?