In the past week or so I've noticed a hollow sounding metallic rattle coming from my car when I start it and also when I turn it off. At first I thought it was an internal engine noise, and I was freaking out, but now I've notice it also happens over bumps and such, so I think its something loose on the car. I can't pinpoint where it's coming from, but it sounds like its more from the front of the car. All I can think of that it might be is some exhaust bracket or something like that, but the noise doesn't seem consistent with that. It's not "clangy" at all, it's more "heavy" and "hollow" if that makes any sense. I'm not sure how else to describe it.

So, any ideas on what this might be? I'll be changing the oil soon so I'll be under there to look around. Any tips on what to look for or things that typically come loose?

Thanks guys.

 

Tap on your catylatic convertor to see if your hear the noise. They will sometimes start to break apart inside & make a vibrating noise. They have this honey comb type material in them. Check make sure to check all of them. My Max is a california car so I have 2 pre cats I at each exhaust manifold & a full size cat near the middle of the exhaust.

 

Hmm...I hadn't thought of that. I've had a cat do that to me before, on my camaro. It didn't make the rattling, but it clogged up the exhaust when all the honeycomb stuff got stuck in the pipe and made the car run like crap. Thanks for the tip, I'll check it out this weekend.

 

Sometimes the heat shield around the cat will make noise also. Even if the material inside the cat is still good. I know how it can be when your trying to find rattles. Good luck.......