Advice on rattle sound from zorst

[Kerwin]

Greetings, I have a 335i convertible and fitted a downpipe and the car has been mapped. After a few months, I have this slight rattle sound coming from the zorst and I checked with my mate who is a BMW technician. He reckons that the acuator has gotten loose therefore the noise running down to the zorst :dunno:. This only happens when I take off from idle. Have anyone here experienced this and is there a solution to it?

Your kind feedabck will be greatly appreciated.

 

[MikeR]

:wave: Im sure you r mate the BMW techie would know better than any of us - especially if he has heard it.
Trust him....maybe he can fix it for you.

 

[M3_devil]

google says.

"The noise appears to be emanating from the waste gate actuator or sealing surface. This noise does not interfere with the operation or power output of the engine.
As per S.I.B. 11 13 07,All N54 equipped E90/92/93 with complaints of a metallic noise from the exhaust system near the engine or turbocharger area . This noise can occur during a deceleration from approximately 3,500 RPM or during a heavy application of the accelerator without a drive gear being engaged"

 

[Richard H]

Could also be a blown flange gasket, on downpipe, do you hear something similar to a dump valve on deceleration?

 

[Kerwin]

Flange Gasket - Checked and perfect. From what i heard, the actuator has a washer kind off thing that has to spin freely and this is what is loose. To get that tightened up, one has to take the turbos out and that means stuff to come out of the engine bay. NO NO. Even if tighten, it will not last that long beacuse of the boost pressure being exerted. So I have a problem cos I like the power increase with the downpipe and map but it has this noise. If i put the normal cats back on, then the noise is gone according to the tech. :banghead:

Does anyone else have this problem ?