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      01-23-2013, 10:36 PM   #4
shah269
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Drives: 2009
Join Date: Oct 2011
Location: NJ

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Quote:
Originally Posted by rking117 View Post
that is Direct Injection. The Newer vehicles have it and it is loud with the hood open. Almost sounds like a diesel. It is normal
I was going to say that.
These new DI injectors run at a much higher pressure than non DI injection systems. And as I understand it, and I may be wrong, per reading up on the matter the fuel mixture as it leaves the injector is under such pressure that it actually creates a mini sonic boom...in this case it sounds like a tick. Add to it that it's occurring in a metallic tube and it just gets louder.
What gets me and I applaud BMW for this, they did not install a plastic insulator over the engine block to cut down on the noise.
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