I have a 2013 G37 Sedan I bought last month, has 130k miles on it. Only mods are an intake and cats have been removed/replaced with test pipes.
just a few days ago I noticed a rattle/ticking sound. Im a little clueless at this point as to what it could be. I checked the oil level and it was low. It had about 1/4" on the dipstick. I added nearly a quart to get the level right but this made no difference. The thing is, I only hear it when in drive. If I'm in park or neutral I have to rev it up pretty high to hear the noise.

Any ideas on what this could be?

 

Check all your fluids. (Change if necessanecessary)
Check for codes. (Address as necessary)
Do the throttle body clean and idle relearn.
Get yourself an oil gauge and make sure your oil gallery gasket ain't leaking interinternainternally.
if all else fails, turn up the radio

 

It could be something as simple as a loose heat shield or an exhaust leak, or something as catastrophic as beginning of an engine failure. We can't help you unless you help yourself by doing further diagnosis.

 

Just did an oil change today with nissan ester oil, no difference.

Haven't cleaned the TB and idle relearn.

If I'm not mistaken, half of 2012s and all of 13s have a newer gallery gasket that doesn't fail like the older models?

I'm leaning towards an exhaust leak based off of some research I've done. Considering I only hear it in drive and I just put the test pipes on a week ago, I feel like this is the likely culprit.. I'm going to check to make sure all bolts are still tight and then I'll try spraying soapy water and blowing air in the tailpipe.

 

​​​​​​PLug the tailpipe with a rag while the engine is idling. If you're leaking exhaust, that noise will get very loud.

 

If you're not leaking exhaust it should actually stall the car.

 

thanks for the idea! I'll give it a try when I get home.

 

Any updates on this issue? I got the same problem, only hear it when I'm moving forward. Nothing in reverse or if I rev to any RPM.

 

Check the washer fluid tank. I had this exact problem and bought a new plastic push pin bolt for it on ebay for $5. The plastic clip had broken

 

It was my exhaust gaskets from the manifold to the pipes. My test pipes came with cheap gaskets or I did something wrong, but they ended up blowing out.
I didn't know an exhaust leak could make such a scary and horrible sound.