Got my gauges in a couple of weeks back and have noticed that under heavy accelleration I get a "squealing" from under the dash. Only seems to happen once the boost goes over 20#. I also get a little chatter vibration noise at times, but its not nearly as annoying as the squealing!!! I have the boost gauge mounted in the dash cubby with a tranny gauge and FP gauge. The noise does not sound like it is coming from the gauge itself, but rather somewhere between the firewall and the gauge.

Any suggestions???

 

check the line for leaks. seen one that did it. but it was leaking around the gauge connection.

 

I gotta agree with Rayls, you have a boost leak somewhere