Rep Power: 0

2002 Civic EX 4 Door 5 speed w/ about 140K Have a rattle that is borderline loud at times but is annoying. Happens when car is in motion or standing still. At around 800 rpm you can just start to hear a rattle, goes away as RPM increases and comes back from around 1500-1800 rpm. Sounds like it is coming from front d side of engine. Does not sound like metal on metal, more like a plasticy or muffled rattle. With windows up very clear inside the car, standing outside hard to hear. Thought it would go away when I replaced the exhaust system from manifold back but no luck. Weird thing is that pressing basically anywhere on the engine will make it go away. Water pump replaced about 30K ago, timing belt & tensioner replaced about 6K ago because of an oil seal leak(didn't think it was worth replacing the water pump at the time with that little mileage on it), D Side,Front and rear mounts replaced about 6K ago. Belts have about 20K on them and seem tight. Any suggestions?
Thanks in advance
Mark

 
Rep Power: 314

Your alternator bolt come loose? The big long one that goes into the side.

 
Rep Power: 512

Nah, when that comes loose, it's a loud metallic tapping.

I'd start the car, pop the hood, and rev it up a bit while under the hood, see if you can pinpoint where the rattle is coming from. Saves you from throwing random parts at it in hopes that it'll stop

 
Rep Power: 314

I bet you it's the exhaust manifold heat shield then. The Area where the bottom bolt is has probably corroded away and is not being held on. But I guess you would have seen that when you changed the exhaust.

 
Rep Power: 0

Manifold heat shield is good, checked that when I replaced the exhaust. Pulled it off, no strange bends, no cracks. Put it back on. Didn't see any cracks in the manifold or any black marks around the gasket but could it be a leaking manifold? Wouldn't that make the same noise regardless of RPM? I checked the other heat shields to make sure they were tight when I replaced the rusted out old exhaust. Will check bolts / belts this weekend. Luckily have another car so this can sit until I figure out if this is something major or just annoying.

 
Rep Power: 314

Sounds like something annoying to me honestly. If it was something more serious it would probably make the noise when you pressed on the engine. Also check your front motor mount.

 
Rep Power: 179

Check your upper catalytic converter heat shield. I had to cut my off a few years ago.

Does it sound like the one in this video?

 
Rep Power: 0

Cat was replaced with exhaust so new cat and new shield. Original did rust out a few years ago and made all sort of noise when it went. I meant to mess with it this weekend since it was nice but didnt have a chance. Thanks for the reply tho. Cant believe with the rattle traps these things are I'm the only one to have this noise, I'll try and take some video later, maybe that will help.

 
Rep Power: 0

Anyone, anything?

 
Rep Power: 314

Kinda hard to diagnose a rattle under the hood without looking at it. We've covered the usuals the rest is up to you Wish I could help more but it's real hard from here.

 
Rep Power: 0

OK, took a video maybe this helps. Can hear it inside the car but not really outside. Think its something with the intake manifold because it goes away when pressing down on the air cleaner. I guess something could have started to come loose after 156K and 11 years.

Thanks
Mark