I posted about this a while back and was convinced it was the heat shields on the cats, I just swapped my Y pipe and while I was down there I checked them and they're solid. I have no idea what else it could be.

It isn't dependant on brakes, it only seems to be noticeable above 40kph and when I'm not on the throttle, but I cant guarantee it hasn't happened when giving it some gas. It sounds exactly like a heat shield would, rattling metal on metal and it seems to be coming from right in front of me near the bottom of the car. It happens mostly when I'm just cruising or letting off the gas before a stop.

I've never heard a throwout bearing fail so I'm not sure if that could be it either, any ideas?

 

Bump. Anyone?

 

Does it happen during bumps?

 

Not really because I'm usually slow over bumps, but its definitely most noticeable when I'm dropping in speed without braking..

 

if it were your throw out bearing, it would rattle in neutral when you press the clutch in and once you release it itll rattle a bit.

 

Okay then its definitely not. I just can't think of anything else thats metal and sheet-like that would make that sound.

 

Since this only happened after you installed the new y-pipe next time you get an oil change and your coupe's on the rack, check how close your exhaust system is to all areas that might make that noise. Any area that doesn't have at least 1/2" clearance might cause the noise at speed. Fixing it is easy with the slightest tweek with a crow bar....Gary

 

It was happening before the install, I just used the Y pipe as a reason to look underneath and check the shields.

It's a little embarrassing, I love my G but the thing sounds like its made of tin when I'm going anywhere that's not residential.

 

I would try checking the undertray and make sure a bolt or etc didn't come loose and fall on there. It would be easy to check. Then maybe check all the mounts/bolts/covers in the engine bay in case something is loose. I had something similar happening in the rear of my car, turned out to be a rear bumper bracket that had come loose. At speed the bumper cover would shake a little, rattling the bracket.

 

Damn, I guess I'm hunting again. I'll report back if I figure it out.

 

There are heat shields throughout the bottom of your car, covering the headers, cats, and muffler. If it's none of those, then if you have a stock exhaust, coupes have a metal can for aerodynamics just in front of the muffler. For reference, it looks triangular from the side, looks like part of your muffler or something, but upon further inspection, you'll notice it isn't connected by any piping and looks like it's there to do absolutely nothing. That thing can be loose and will rattle like a heat shield. You can either tighten it down or get rid of it.

 

I never though to check the headers, I didn't even realize they had heat shields. It's definitely coming from the front of the car, so I don't think its the muffler. It also sounds like its on the driver side so it could be the left shield on the manifold. I'll take a look, thanks.

 

IMO, it all sounds the same from inside the car.

 

Hey adam do have an auto or 6mt?
Have you checked your oil level lately?

I think I asked this in one of your older threads, but doesn't hurt to ask again.

 

6mt, I check the oil every time I fill and it's always been good. No consumption so far and I've had it for about 900km.

Well, no noticeable consumption.. And I ruled out clutch issues for sure, I can engage and drop the clutch when its rattling with no effect at all.