[diddlkiss]

Hey everyone,
I get the siren noise last week,in my new car,the Z4 35i.
the mod only procede v5 and runing the 7-29 autotuing map.
when I install the procede,I got the noise.The same noise in my 335i also.
the Z4 only 3,400miles and the 335i 36k miles.
I cant found some thread.
the car so fast no leakage or oil Consumption.
any advise.
thanks

[E90Company]

Really? I've extensively studied this. Been through multiple turbo sets because of it as well. Don't worry about it.

http://www.e90post.com/forums/showthread.php?t=769587

[Jeff@TopGearSolutions]

Originally Posted by E90Company

Really? I've extensively studied this. Been through multiple turbo sets because of it as well. Don't worry about it.

http://www.e90post.com/forums/showthread.php?t=769587

[Ilma]

Don't Worry About It

[USAF Rick]

I never got the siren until I started modding my car, but I've read many times over to not worry about it.. so I guess I'm not.. Lol.

[Ferruccio]

I get the siren. I've been getting it for over a year. Boost and performance hasn't changed one bit. It's been over 10000 miles with no change to its intensity. I think it's just a normal property of the turbos that sometimes is there and sometimes isn't. Do you have an upgraded, noisier intake system such as dual cone intakes? That might amplify any noise the turbos are making. I know that my siren noise got much easier to hear when I changed the intakes.

Oh, also, if you are at high altitude, your siren noise will be much higher. You will hear a siren noise that eventually gets drowned out by the sucking noise of the intakes. But, at high altitude, for the same amount of sucking noise, you need a much higher turbo RPM. So, under normal use, you will probably perceive a louder and higher pitched siren sound when at altitude.

[ihc95]

When I had the siren noise my turbos weren't boosting at all. They were replaced under the wastegate warranty.

[diddlkiss]

Originally Posted by Ferruccio

I get the siren. I've been getting it for over a year. Boost and performance hasn't changed one bit. It's been over 10000 miles with no change to its intensity. I think it's just a normal property of the turbos that sometimes is there and sometimes isn't. Do you have an upgraded, noisier intake system such as dual cone intakes? That might amplify any noise the turbos are making. I know that my siren noise got much easier to hear when I changed the intakes.

Oh, also, if you are at high altitude, your siren noise will be much higher. You will hear a siren noise that eventually gets drowned out by the sucking noise of the intakes. But, at high altitude, for the same amount of sucking noise, you need a much higher turbo RPM. So, under normal use, you will probably perceive a louder and higher pitched siren sound when at altitude.

Procede is the mod in my Z4 only.
I dont have DCI or other MOD.
and in Qingdao the altitude only 32ft...

[diddlkiss]

any advise

[Snaggletooth]

Down the road, performance is going to decrease but it is gradual. I would try to put aside money for upgraded turbos when a replacement is due.

[Bme30]

I have brand new oem turbos and they do it too. Nothing to worry about.

[Wedge1967]

My old turbo's made little noise, but they didn't spool till 4k and made loads of power. Now that I have new turbo's I'm enjoying the sound of the turbos spooling, which most mistake for siren. If you had a siren, you would know because it would be SOOOOOO LOUD you wouldn't want to drive your car.