A few months ago I started to hear a pretty minor rattling noise around 4000RPMs. I don't go up that high that much, but recently I started to hear louder rattling at around 3200RPMS or so. It almost sounds like something is vibrating under the engine bay. When I'm accelerating, it's smooth, and a prominent rattling for a split second as it goes through that rpm range, then smooth again. It also ticks/knocks a bit when it's cold, don't know if that is related.

any ideas?

 

Have you checked for a loose or cracked exhaust heat shield?

 

the two bolts seen from the top of the engine bay are tight and I pushed down on it and it doesn't move or anything. I guess I can check more in depth. Is that something that could only vibrate at certain RPMs?

 

geez im in the same boat but i dont have any heat shields and i hear the taping as well at diff rpms

 

so I had my friend listen while I revved the engine and he was pretty sure the sound was not coming from the manifold area but the cat. I've looked and reached under there and there seem to be several heat shield like pieces but nothing looks rusty or loose.

Im probably not going to have time to get it up on jacks and take a closer look until this weekend, but does anyone know exactly what could be causing the sound and how to fix it?

 

The heatshields on my cat were some how broke and I just rewelded them and the sound went away.

 

its your o2 sensor in the front i had the same problem

 

Could be that also.

 

throw out bearing? That's what I was told on my ek hatch. Same rattling noise when I disengage from clutch. Goes away when I step on the clutch. No noise when i'm driving.

 

Not to thread jack, but if it goes away when the clutch is pushed in it is not the throw out bearing.