Hi all,

This is me asking for some help.

I have a 05 225 QC with an APR stgIII+ kit in it.
I use APR's turbo-back 3" exhaust.

as of recent, when I get the car into boost (right around 4000rpm) with full throttle, I hear a noise that sounds like a heavily vibrating piece of metal coming into contact with another piece of metal.
I hear this windows-up also.

It is recent, and has me concerned. Could it be the Downturn and DP? would that mean something has come loose?
th eonly other insight I can provide is that the boost-gauge has been sometimes sitting at a VAC of just 15 in idle.
Also the gauge, with the engine off, does not place the needle dead-center in the "off" location (its a box) anymore.

please help me out guys.

thanks, and greetings.

 

It could be the dp hitting since the dogbone bushing is worn. If so, its like $40 for new stiffer inserts. If you dont have them, you should get them.

The boost gauge should be at 0 when the car is off. If its not, your boost gauge is most likely off

 

Hmm I get a brief vibration around 2200 RPM. Think this could be the DP? Mine's stock...

 

It could be anything... Anything can have a sympathetic vibration ate any rpm. My Bimmr had one at about 2400rpm that I never was able to find in two years. I would start with the exhaust first from the block backand make sure nothing is touching or rubbing.

 

Well, thanks for the responses fellas.

I will throw the thing up on a lift next weekend and check whats going on. I don't have a garage right now and its been raining cats and dogs, otherwise the bumper would be off already along with some jack-stand action.

I have a feeling its the Dp because it happens just before boost (and its onset of high frequency vibrations).

sure hope its not the turbo itself though []