[finleyg]

New to the 335i, bought an 07 with 22,000 miles on it. Previous driver was a neighbor, never heard him beat on the car.

Under acceleration, the car makes a rattling sound, as if there was a loose flashing or worse, could be main bearings. I had test driven a 328xi with more miles which made no such noise. Power is great and there are no engine codes, but sounds like it may be getting worse. Has anybody had any main bearing or valvetrain failures without huge boost or racing or loss of oil pressure??

I have read the threads about the wastegate flutter, but it sounds more regular and deeper than that.

Thanks in advance for any help!

Fin

[E90xi]

You might make sure it has premium fuel in it and not just regular fuel. Your neighbor might have just put regular fuel in it because he didn't "beat" on it. The sound you are hearing could be engine detonation, which can be very harmful to the engine. Make sure the correct fuel is in it.

[finleyg]

That's a good thought, but has gone through three tanks of 93 with me. Also, the sound is not as sharp as a typical detonation ping.

[shadowcoder]

When stationary and pressing on the gas, do you hear the noise/rattle?

[Viper3812]

Is it coming from the engine itself or around the turbos? There is a bulletin for a rattling sound in the turbo area. Take it in to the dealer and they will replace the wastegate actuators if that is the case. If you hear it from the engine itself I have seen a few N54 engines come in with scored up cam ledges.

[finleyg]

Viper, I will have to test the non-load issue, but it grabs revs so fast, who knows. I will also try to determine whether it is a turbo sound or the motor. Unfortunately, it sounds like motor, but I will check that tonight.

Thanks in advance for your good advice.

Fin