problem alfa 159,hiss from the engine compartment

[sportknight]

Hi guys,I am writing for my 159

practically this is the problem,if I accelerate gradually in the second(where you note the problem) when the car arrives almost at the peak by one shot,after which the pressure drops and then gets up again.in that moment, you hear a noise type hiss of air, a frrrrrrrr

I then often hear the same hiss durable that I thought it depended on the wind, but probably not,I also tried to decelerate,accelerate,put in neutral, etc.. but I can not realize why sometimes does and sometimes not.

I thought of a hole in some sleeve or in the intercooler, but it does not smoke and does not lose the prestazionio,there is only the one shot when it goes to peak the turbine

ideas!!

[ugoboss]

these cars have problems on the studs of the exhaust manifold that come loose and sometimes they break causing noises similar to yours, check.

[sportknight]

Already changed in advance last year and it was still

[overbooster]

check the metal collar between the turbo and the catalyst sometimes I found it a bit unscrewed, you will find dust black close to the sheet metal heat shield to the turbo?

[sportknight]

then,I am set to do some tests and the noise is randomly depends on a guard broken

but what you hear when the turbo goes into pressure safe no

lately, I have deleted the precatalizzatore with a pipe, and then I close the clamp,the problem is that the defect did already before

the most worrying thing is that it gives me this pressure peak,then drops and then goes back, it seems to me so normal, so much so that is also annoying

by increasing the pressure of the turbo of course, it also feels more

I thought I'd lower a little the curves of the vgt so as to keep the geometry a little more open, and then not have the piccata strange because I remember that from my review of the software 138-889 the one after there was a difference in the management of the geometry

I will try in the next few days and I'll know

[overbooster]

also my gives the piccata and the VS 160-252 with or without swirl is the same thing I thought that they were their that open of a bang due to dirt and no or it is a strategy related to them make up the pressure x increase of the turbulence with the swirl closed in x then open

[sportknight]

then piccate make your,mmm, and then you have not tried to resolve?
to long according to me some problem it would create

[overbooster]

Anyway, it is only at partial loads, the tablet does not

[overbooster]

No Xké many people have all this let's call it a defect, I have removed the swirl x to avoid damage to the engine but were still working

[xathanatosx]

Anyway, to me it does and it also does it to several of my friends have the usual engine.
In practice, by the gas, and you can feel kick in **** a little less than 3000 rpm and note the pressure drop and then increase again.
I noticed but with a form if I press at the bottom does not happen......I don't know give me explanation