UPDATE!!!
1) Took the car to Fast Lane Import auto Repair in Smyrna and was told that they wouldn't look at my car because it was too highly modified... They told me the sound sounded bad and that I needed to trade the car in... This is just ludicrous so I decided to get a second opinion.

2) Took the car to Topspeed Motorsports in Alpharetta. They thought it was the VTC solenoids failing so they replaced them. This did not fix the issue and upon further inspection I was told the oil pressure was so low it did not even show on the oil pressure gauge. They told me my main bearings were worn to a point of my needing a complete engine rebuild... I was told that a rebuild would run me around $7k. This seemed ridiculous to me so I went for a third opinion.

3)Dropped the car off with Pete the engine man in Braselton, GA just by Road Atlanta. He had the car for a few days and tested the oil pressure and came back fine! Upon further inspection he has concluded that it is wear in the drivers side cam sprocket. The rattle is caused by play in the chain and the sprocket. He said I would need to remove the timing cover to get at the sprocket and at that point I should probably replace most of the replaceable parts on the front end. He said that the rattle will not cause any damage and in the long run the rattle may get worse as the sprocket wears more but won't damage the engine.

I am very happy to have found the issue and did not need an engine rebuild. Hopefully this thread will help others in the future.
Thanks!



Hey guys,
I am hoping one of you have run into this problem and know the fix. When I am driving around 1200-1400 rpm in any gear i am hearing a rattling noise that makes my car sound liek a diesel truck. It really sounds like something rattling to me but maybe one of you know what it could be. Other than the noise, everything seems to be normal. Car still pulls strong.

here are links to some videos I took this afternoon.






Thanks for any help!!

Mods:
Stillen Gen 3 intake
MD ART pipes
Fast intentions CBE
Custom dyno tune @Z1 Motorsports

Hey man my car does the exact same thing, whenever I'm driving really slow I can hear it. Sounds real bad, I'm thinking it's my throttle bodies. After I cleaned mine is when I started hearing it. I dont know what it is but now I see I'm not the only one with this issue....................

Hey Kiwini thanks for the reply. I think I have actually found the problem! I recently had hotchkis sway bars installed front and rear and I have the Zspeed aluminum under shroud. They had to cut a couple holes for the grease fittings to come through the shroud. I removed the shroud and the noise has stopped!


Here are a couple pictures of the shroud and you can see where it was rattling by the holes.




I'm gonna drive it some more and see if I can replicate it.

So I drove t again and it's still making the noise. I was able to replicate it by standing in the brake and revving to 1200 rpm. The sound is definitely coming from the timing chain. I'm thinking that it might be the chain rattling against a guide or the cover. I can feel the vibration when I touch the timing chain cover.

Anyone else have this problem?

The G is in the shop now. Hopefully I can update later on today with a resolution.

It does sound like timing chain noise...

chain.

Thanks guys. I'm having another shop look at it on Monday. The shop I was at told me that I had low oil pressure caused by worn main bearings and need a complete rebuild... Im getting a second opinion on Monday. I am having a hard time believing the oil pressure is as low as they say since it doesn't make the noise and has no hesitation at any other RPM.

I will definitely check back in here when I find the solution.

Updated the first post with solution!

How did you fix this issue and how much it cost you? I am having the same problem, may car would sound like diesel truck if i have the rpm stays at 1300-1800. Thanks

Does the sound go away the moment you let off the throttle? It sort of sounds like that's what's happening.

You're probably going to need someone to throw a mechanics stethoscope on it and give you a diagnosis in-person.

Almost sounds like a pulley bearing going bad to me, sort of has that "swishing sound" that pulleys make when the bearing goes to ****. Definitely don't hear any "diesel knocking sound" like your description suggests.

yah it’s weird how it like phases on and gets louder and then just stops randomly and with lift off.

some times you ca. Clearly hear it’s alternating the sound and it seems to move or at least go loud soft loud soft loud like a clack clack clack click click click clack clack clack click click click. From 1200-1400 then it stops entirely like a switch turned off.

I heard ( read ) somewhere it could be the hydraulic timing tensioner losing oil pressure and allowing slack on the chain. Which could be plausible with the sound? No?

Again, gonna have to get a mechanics stethoscope on it to determine where EXACTLY the noise is coming from. A smartphone hanging out the driver window isn't going to really help anyone make a diagnosis.

If you had someone else replicate the sound while you stood at the engine bay and made a video from that perspective it would HELP but probably still going to need to get a stethoscope on it.

EDIT: I would check the oil level though to make sure you aren't low.