Strange Turbo sound

Grapee · Post by **Grapee** » Mon Oct 19, 2009 10:09 am

Hi All!

(Maybe this has been already discussed, sorry if so!)

I had to fix my Cooling system this weekend (thermostat exchange + radiator cleaning - i hate the DIY cooler additives for leaking systems-they plug everywhere :/) and therefore i had to remove the Airfilter housing. Testrunning the system i heard something, i didn't wan't to hear....

Link (need 10 posts to do it easier

):

h t t p : / / g r a p e e . u w . h u /volvo/shrek/turbo.m4a (WinAmp plays it)

I think, this isn't how a healthy Turbo should sound...someone an idea, what could be wrong?

I have a non standard open blow-off fitted (no whistle

) and it does the job - pedal to the metal on the street and it releases as it should (noticeable shhh with the Richmods ~1bar

), but without load it's strange.

Anyone help?
Thanks!!!

Derek · Post by **Derek** » Mon Oct 19, 2009 3:02 pm

that sound is compressor surge and its a good way to kill a turbo. the spring in the blow-off valve will be to strong

felyx · Post by **felyx** » Sat Oct 24, 2009 12:49 pm

make sure the BOV is located as close as possible to the inlet manifold , and also check the piston seals on the BOV (they are quite cheap) when they are wearing out it can sound like a cross between a fart and somebody badly trying get a note by blowing on a blade as grass cupped in there hands .

Grapee · Post by **Grapee** » Mon Oct 26, 2009 1:19 pm

felyx wrote:make sure the BOV is located as close as possible to the inlet manifold , and also check the piston seals on the BOV (they are quite cheap) when they are wearing out it can sound like a cross between a fart and somebody badly trying get a note by blowing on a blade as grass cupped in there hands .

BOV is located at the factory place.

Will check the seals again, thnx!

outlawmorga · Post by **outlawmorga** » Wed Nov 25, 2009 3:25 pm

It sounds like the spring inside your dump valve is nackered either try another one or get another spring possibly a tighter one. It's letter the air out to quickly it should only dump once the preassure gets to a certain amount.
The other thing it could be is it's closing to late and stalling the turbine wheel which means you need to get a weaker spring.