motor noise at 12+lbs of

[87gnfan]

i need some help,when i step on the gas and the turbo spools up and gets up to 12 lbs it starts making a noise that sounds like air rushing out somewhere.i have checked my intercooler hoses and they all good and hose clamps tight.checked vaccum lines and cant find a leak,but my guage is pulling 16 inches of vaccum at idle.im hoping i dont have a blown head gasket but i have no water in my oil and the radiator holds pressure.can someone please help me................thx

 

[forcefed3.8's]

The headgasket could be leaking air from the bottom of the cylinder. Look for carbon trails and graphite from under the head.

 

[notacarlo]

Is this a new noise?

Have you had much experience with turbo cars?

If you have an open air element, the turbo is much more pronounced.

 

[stagemonster]

dose it sound like a surging sound.

 

[87gnfan]

found it

it was the down pipe going to the cat conv.it was loose so i tightened it a tack welded it,now noise is gone....thx for the help.

 

[Amelio]

Just a suggestion but if you have air leaking there it is a pretty good indication you have a lot of back pressure, you may want to look into a better exhaust system ...your performance gains would be noticeable.

Just a thought.