I am 100% sure of this , see car and driver review below
"And when a 328i pulls up, a pronounced ticking from the injectors also gives away its identity. BMW tried hard to suppress the N20’s diesel-like injector noise with an acoustic cover and a thick rubber pad on top of the engine, but it remains somewhat noticeable."
http://www.caranddriver.com/reviews/...-drive-reviews
FYI the 125i and 328i engines are identical