wierd rattling sound coming from engine bay

ilikecereal · 05-17-2005, 10:53 PM

i've recently noticed a really wierd rattling sound coming from my engine bay and i don't even know how to diagnose it. it sounds like it's coming from the back of the bay maybe right under the firewall or something. i asked someone who knows some stuff about cars and he said it's my heat shield for my catalytic converter, but i don't know how accurate that is. it's really annoying and it bothers me. any ideas of what it is? is he right? thanks guys

blackeagle · 05-18-2005, 02:31 AM

Is it there all the time or just certain engine rpm's or speeds?

ilikecereal · 05-18-2005, 03:19 AM

Quote:

Originally Posted by blackeagle

Is it there all the time or just certain engine rpm's or speeds?

it's there all the time.

blackeagle · 05-18-2005, 03:42 AM

I doubt that it is the heat shield. It is more likely the catalytic converter. The insides on mine disintegrated and I found pieces of it scattered through the whole exhaust system all the way back to the muffler. One way to check is to grab the pipe(make sure it is cool first) just behind the catalytic converter and shake it to see if you hear any pieces rattling around in there. I bought a new catalytic convertor for $130 at catalyticonverters.com and it included the pipes from the exhaust manifold to the resonator pipe. It was an easy DIY install.

Sega Saturn · 05-18-2005, 04:05 AM

I had a loose hanger on my muffler once, and the pipe was rubbing, where it goes over the rear a-arm

my99sl1 · 05-18-2005, 06:28 PM

Quote:

Originally Posted by blackeagle

I doubt that it is the heat shield. It is more likely the catalytic converter. The insides on mine disintegrated and I found pieces of it scattered through the whole exhaust system all the way back to the muffler. One way to check is to grab the pipe(make sure it is cool first) just behind the catalytic converter and shake it to see if you hear any pieces rattling around in there. I bought a new catalytic convertor for $130 at catalyticonverters.com and it included the pipes from the exhaust manifold to the resonator pipe. It was an easy DIY install.

i agree with him

that has happened to my car and they bent the heat shield back into place and it wasnt that so i had it looked at another saturn dealer and they said it was the cat so they replaced it for free since it was still under the 10 year/100,000 mile warranty. Then later the sound came back and it got worse and turned out being that i blew a rod through the engine block.

ilikecereal · 05-20-2005, 06:17 AM

Quote:

Originally Posted by my99sl1

Quote:

Originally Posted by blackeagle

I doubt that it is the heat shield. It is more likely the catalytic converter. The insides on mine disintegrated and I found pieces of it scattered through the whole exhaust system all the way back to the muffler. One way to check is to grab the pipe(make sure it is cool first) just behind the catalytic converter and shake it to see if you hear any pieces rattling around in there. I bought a new catalytic convertor for $130 at catalyticonverters.com and it included the pipes from the exhaust manifold to the resonator pipe. It was an easy DIY install.

i agree with him

that has happened to my car and they bent the heat shield back into place and it wasnt that so i had it looked at another saturn dealer and they said it was the cat so they replaced it for free since it was still under the 10 year/100,000 mile warranty. Then later the sound came back and it got worse and turned out being that i blew a rod through the engine block.

so do you think this is a problem i should get checked out right away? or is it something that can wait many months until i get new exhaust and hopefully new header?

my99sl1 · 05-20-2005, 06:37 PM

well like i said it could be either the cat or your rod

i would get it checked out right away just to make sure its nothing major

scottyr94 · 05-21-2005, 03:05 AM

Sounds like a cat problem to me. If it was a rod it would be knocking sound, and would louder and faster with increased rpms. My old wagon has had a bad cat for quite some time and I'm still driving it. Only problem you may have is they can get very hot and there are stories of them starting on fire, don't know about Saturns or not. The one on my Saturn was shot for over 4 months before I just decided to cut it off.