Hey guys, recently bought an 05 g35 coupe 6mt, and my friend bottomed it out really hard while teaching me how to do hill starts. Now there's this rattling/clicking noise that happens whenever I accelerate (mostly in 2nd/3rd gear). It doesn't happen if I'm revving in neutral. I took it to a muffler shop and they could see the mark from the bottoming out, but said everything seemed tight, they thought maybe a weld on the inside of the exhaust was stuck in the resonator - but I don't understand why the noise is inconsistent. I've read people saying it needs an oil change but there's plenty of oil, maybe it's bad oil? Previous owner didn't seem to know what he was doing. Either way it's making me nervous and I was wondering if anybody had this kind of issue before. I took a mechanic on a ride along but he said he couldn't really diagnose it until it gets worse. I'll try to post a video sometime soon if nobody has any advice.

Thx
Phil

 

Does it only happen on 2nd and 3rd gear, but not any other gear? That is strange.

Are you also aware of the G35's rear axle clicking issue? Mine has that problem, where you will hear a clicking sound in 1st or 2nd gear at low speeds from the rear.

 

Maybe the heat shield?

 

First, I don't know how you bottom out doing hill starts, so you're leaving something out to this story.

Next, check oil level when engine is cold, like after leaving it parked overnight. I get a noticeable timing chain rattle on acceleration when my oil is 1/4-1/2 qt low.

What part bottomed out/scraped? Could also be a heat shield like Venom suggests.

 

I was going through the threads I started - and I realized I never got any notifications for responses which is irritating. It just makes me think you guys are jerks who ignore my threads :P

To anybody who might get this notification - my friend was doing a u-turn on one of those dirt turn-around things on the sides of narrow mountain roads, that's how he bottomed it out lolz. He did scrape the underside of my car, but that wasn't the problem.

It's a pre-ignition detonation rattle, ping, whatever it's called. I have to get it tuned out.