Rep Power: 182

I recently installed an AEM short ram intake on my EM2 and have been driving with it on for about 2 weeks. Since then, I've driven in heavy rain twice and each time, there's been a nasty rattle coming from under the hood or somewhere in the front half of the car.

After a couple miles driving in the rain, when I come to stop or start moving slowly, the rattle shows up and it's pretty violent. Is this because of my air intake? Is it sucking up water by any chance? I wouldn't think so because it's bone dry when I pop the hood to look.

Could it also be my catback exhaust rattling? Llike some sort of thermal shock on the mid pipe? Either way, it only happens after I drive in wet conditions for a while... any ideas?

 
Rep Power: 286

Strange. I'd start by going over everything and checking to make sure it's tight.

 
Rep Power: 182

OK, scratch my original complaint.
I'm pretty sure now that it's the exhaust.

With 2.5" inch piping, it's likely that the cold rain on the bottom of the pipe is cause it to warp and hit the underbody of the car.

I've tried to get out of the car to find the exact spot of the rattle, but everytime I get out, the rattle stops

 
Rep Power: 314

To add to this. My 5 speed civic goes "Klunk" every once in a while when I accidentally let my RPMS drop below 500 due to a stupid shift. It's the short ram intake literally bouncing and smashing into the hood due to the low RPM engine bog / bounce. I fixed it by putting hardwoord floor pads on the hood where it bounces off. Though not a permanent solution or fire resistant, it's helped. I still get it when I bog down but it's improved a lot. Just a thought, check if the intake is hitting the hood, you will see the paint wearing off the intake where the impact is happening, and then find your own fix for it if that's the case.

^ Mine might be due to a cheap EBAY pipe.

(Hardwood floor pads are the felt pads that go under chairs and such to protect your floor)

 
Rep Power: 513

I'm willing to bet it's the catalytic converter heat shield.

 
Rep Power: 182

Care to elaborate? It's defintiely a possibility, but I'm leaning towards the intake or exhaust pipe being the culprit because I just added them in the past month.

@BlueEM2 - I put a piece of foam between the intake pipe and the hood, but the rattle is still there. I think I've ruled out the intake.

 
Rep Power: 513

that heat shield is fairly flimsy, located on the underside of the car. I'm talking about the one between the car and the cat, not the one welded onto the cat itself. The one that's actually bolted/riveted/attached to the car itself