Ok, so I have the rattle from my cat at 1800 RPM. I know there has been a service bulletin put out about this. Does anyone have access to the bulletin or have any tricks to fixing this rattle? I've tried tightening the bolts on the heat shield to no avail...thoughts?

 

The heat shield on top of my cat ('99 LX I4) is ratteling too, I'm also interested in seeing the service bulletin.

A friend of mine with a 2000 EX also had a ratteling heat shield, it was his bottom one so he just cut it off. Does the bottom heat shield really serve a purpose?

 

Whoops, looks like I forgot how to post, its been so long. This is about my 94 accord EX and as far as I know, this is the original cat, but there is an OEM replacement cat-back. Hope that helps.

 

i seem to think there is/was/is supposed to be some sort of mat in between the heat shield. that may have been removed/destroyed at some point and may be causing the rattle.

 

Mine rattles now too. I just got my b18c put in my 95 civic coupe and the cat is rattling a bunch. I guess I should probably replace it for a bigger cat anyway with 2.5inch going in and out. Oh well

 

just get under there and see if your heatshield is loose. mine was rattling and i jacked up the car and pulled it off with one hand. it was completely loose just laying on top of my cat!!

 

Thats the thing thats killing me...everything is tight as can be under there. The only other theory that I have is the heat shield for the exhaust further back on the car has some play in it. However, after stuffing some rubber up there to stop that, the rattle's still there. Its not even THAT big of a deal, its more the fact that I can't source it and fix it thats killing me!

 

I have a 96 Accord EX that was doing the same thing....

My issue wasn't with anything being loose, but that the heat shield had rusted away AT THE BOLTS. It had simply developed a crack all the way around one or two of the small bolts until it was able to rattle me insane. I just lifted up the car and helped it on its mission by ripping it out. Take a really close look at everything around the heatshield fasteners and give it a good shakedown (when cool of course). If you're not looking specifically for a crack you'd probably never see it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Schmitey &raquo;</TD></TR><TR><TD CLASS="quote">I have a 96 Accord EX that was doing the same thing....

My issue wasn't with anything being loose, but that the heat shield had rusted away AT THE BOLTS. It had simply developed a crack all the way around one or two of the small bolts until it was able to rattle me insane. I just lifted up the car and helped it on its mission by ripping it out. Take a really close look at everything around the heatshield fasteners and give it a good shakedown (when cool of course). If you're not looking specifically for a crack you'd probably never see it.</TD></TR></TABLE>

you are onto something

after doing my exhaust all those years ago, the rattle changed its sound, and became more prevelant. i ripped off only part of the shield, so chances are there is a crack that vibrates right at whatever fequency the engine creations vibrations at right around 1.8k (similar to opera singer breaking glass kind of physics). When i finally getting around to changing the oil and cleaning my filter, ill look for any cracks to confirm this

 

Yeah mine was the same way...it would only vibrate at certain throttle positions at certain RPM's. It took me a while to confirm that I did indeed even have an exhaust rattle because it was so infrequent...but its gone now!