# turbo sounds like siren



## dburone (Apr 2, 2004)

A couple of days ago my turbo started to sound like a siren before boost comes, i guess its when it startes spooling.
Any idea what it could be?
it s like an ambulance follows me everywhere!!!


----------



## wes (Apr 30, 2002)

Do you have a vacuum/boost leak? What does the gauge read under vacuum @ idle?


----------



## dburone (Apr 2, 2004)

at idle it reaches -20psi
it startes to sound like a siren at around -10 or -5 psi and until 0psi o 2psi then it goes all the way to 8psi with the normal turbo sound.


----------



## Zen31ZR (Mar 24, 2004)

I had an 86 Dodge Daytona that did something maybe similar, but the opposite way. It sounded like a siren when spooling down off boost, like when I'd be coasting down to a stoplight. I was told the turbo was going out, but had no problems in over 2 years with it. I'd be inclined to say maybe you have a pre-turbo piping leak. Where does your boost guage read from, directly in the intake manifold?


----------



## dburone (Apr 2, 2004)

it sounds like that in the range i said, either way, accelerating or decelerating, at this moment im under 0psi, so turbo might just be spooling but not producing real boost.
Full boost is achieved whith no problem, the gauge meters from the intake.
The sound comes from the exhaust side of the turbo, today ill try to find out more if i can.
thanks


----------



## wes (Apr 30, 2002)

FWIW it is not -psi is is vacuum. It is measured in inches and expressed as inhg. So if you are hitting 20inhg that sounds just fine. 

I would check for exhaust leaks or something, but if the car is building boost just fine and running OK I wouldn't be too worried.


----------



## dburone (Apr 2, 2004)

yes, boost builds up just like it did before the sound, but its not a nice sound at all!!
ill contnue investigating
thanks


----------



## dburone (Apr 2, 2004)

Well, this is what i found out, not much, but not good...
I used a sthetoscope to listen to the turbos components and found out that the sound comes from the center seccion of the turbo, y guess things arent good in there!!
How hard is it to get in there and change whats necesary? is it posible to do without having to balance things back??
thanks


----------



## wes (Apr 30, 2002)

dburone said:


> Well, this is what i found out, not much, but not good...
> I used a sthetoscope to listen to the turbos components and found out that the sound comes from the center seccion of the turbo, y guess things arent good in there!!
> How hard is it to get in there and change whats necesary? is it posible to do without having to balance things back??
> thanks


No it must be balanced unles you buy a completely new CHRA and swap it in place of your old one. I would send it off for a rebuild or find a new CHRA.


----------



## dburone (Apr 2, 2004)

But if the Bearings are bad and thats what i need to change, that doesnt affect balance, right?
The shaft and propellers have to get out, but i should mark the original position and the balance would be lost...
Correct me if im wrong... i never did this but it seems like im going to...


----------



## dburone (Apr 2, 2004)

It looks like the turbo has too much shaft play,I dont know what has to be changed...
Where could i get a complete and already balanced CHRA to fix the turbo?
Thanks..


----------



## dburone (Apr 2, 2004)

looks like the turbo recieved too much heat some time and the turbine wheel got a little eroded


----------

