[jer335]

Recently had my turbos on my 07 335i replaced by BMW under the 8/82,000 warranty. I noticed that under light acceleration there is some noise coming from the engine bay. This occurs only during 1st-2nd gear between 1500-2800 RPM. The best way for me to describe this noise is like a metallic whoosh sound, similar to waste gate rattle. I know that the exhaust flap makes some noise but I unplugged the exhaust actuator to determine if it was the exhaust and the sound was still there. The sound doesn't occur during WOT. Any input or advice on to what could be causing this noise?

Noise only occurs during acceleration when RPMs rise.

Link to video:

[taz8it]

I am having the same problem. Usually 2nd and 3rd gear from 1500 rpm to 2800 rpm. From what my indy told me it is internal. A stuck lifter or a bearing. I am not so sure. I think it has to do with something lose under the car. My Car is going to the stealership tomorrow. I will keep you posted.

[jer335]

Originally Posted by taz8it

I am having the same problem. Usually 2nd and 3rd gear from 1500 rpm to 2800 rpm. From what my indy told me it is internal. A stuck lifter or a bearing. I am not so sure. I think it has to do with something lose under the car. My Car is going to the stealership tomorrow. I will keep you posted.

Thanks! Please let me know what happens!

[jer335]

I found this http://www.bimmerfile.com/wp-content...wn54update.pdf. This does describe the sound. However, does the N54 07 build have mechanical waste gates?

[jer335]

Anyone?

[skim7x]

That sounds like wastegate rattle... Although it should happen in all gears... And is usually not that loud unless you have cattless dp's

[jer335]

Originally Posted by skim7x

That sounds like wastegate rattle... Although it should happen in all gears... And is usually not that loud unless you have cattless dp's

Is it possible the dealer replaced my turbos but not the waste gates?

[skim7x]

Originally Posted by jer335

Is it possible the dealer replaced my turbos but not the waste gates?

With BMW mechanics, you never know, but they are not supposed to replace parts of the turbo assembly... they are supposed to replace the entire set together.

[jer335]

Originally Posted by skim7x

With BMW mechanics, you never know, but they are not supposed to replace parts of the turbo assembly... they are supposed to replace the entire set together.

are the actuator arms a part of the assembly?

[jer335]

Originally Posted by skim7x

That sounds like wastegate rattle... Although it should happen in all gears... And is usually not that loud unless you have cattless dp's

Also, IIRC, isn't waste gate rattle heard during deceleration when RPMs drop. This symptom occurs during acceleration when RPMs rise.

[Snypa]

Sounds like waste-gate rattling to me too.