So after the change, ive noticed after i drive (say 20km) and i am idling, it sounds like something is rattling fairly loud inside the cabin (nothing is though). when i let off the brake and start going forward, it goes away.

I poped the hood and noticed the engine was making a loud whistling type noise. Any ideas? maybe i put to much, but would that cause this?

 

Just to add. I only hear it at the end of a drive. I don't notice during.

 

I doubt that changing to a different brand oil would make any difference. Did you use the proper weight oil?
Using the recommended ester oil is suppose to quiet the engine, a bit, compared to other oils.
Let the engine cool for 10 minutes or so after shutting it off and check to make sure the oil level reads at the full mark, on the dip stick.
It may have sounded that way all along, but after you changed the oil you are paying more attention to see if everything went well.
IMO, the G engine is the worst sounding engine, at start up, that I have owned and I've owned quite a few cars.
I realize that it is just the nature of this engine and I'm not concerned about it as far as reliability, but I still don't like starting the car when someone is standing near the car. It sounds like crap.

 

I did use the proper 5w30 weight. I'll double check if it's over fill. If it is I'll empty some when I get home and see if it corrects itself.

 

If it's slightly above the full make (maybe a mm above the little circle) is that too full?

 

No that is fine. Is the dip stick put back in its place properly? You didnt drop a tool? Leave the plastic belly cover loose or anything like that? The only thing I can think of regarding the whistling is your intake.

 

I'll double check everything. I just removed my r2c intakes and replaced te stock ones. I'll double check all the connections. I don't believe I dropped anything but I'll look. I'll start it up and see how it sounds on the way home from university.

 

Yeah make sure all of the clamps and stuff are tight enough and that the air boxes are properly mounted. There is going to be a slight whistle if you listen closely. My car has it also.

 

Well the boxes aren't properly mounted now that I think of it. I could not get them back into the rubber grommets. But that wouldn't cause a in cabin rattle noise