Good points.

 

ok, so ive had the car for a little over a month now, and the noise is more of a rumble, it sounds like this video. it makes that light rumble sound. The noise does get worse depending on how the day is. Ive driven on a hot day it does the rumble every time i go to neutral. Ive driven at night and it does it occasionally. Tonight it was very humid and it was doing it a lot. heres a vid i found on youtube that sounds like it. <iframe width="420" height="315" src="http://www.youtube.com/embed/4k2E04ECYfY" frameborder="0" allowfullscreen></iframe>

 

http://youtu.be/4k2E04ECYfY

 

That engine sounds "off". Perhaps valve clearance is incorrect or plugs or injectors need attention. I'd say it's not in a good state of maintenance or tune. It might be time to list what kinds of mods have been done on the engine. (ie. bad or improper plugs, injector maintenance?, coolant bypass mod?, weird aftermarket gimmicks, fuel, etc.) If your engine sounds "like" that in the vid, you need check that basic stuff are all in order.

 

Had this issue, turned out to be the knock sensor. Replaced it and doesn't happen anymore.

 

well the car is stock, other than an air filter, and i just did some maintenance like all the fluids, spark plugs, and valve cover gasket.

 

i was thinking of doing the valve adjustment now