Hey guys,

After trawling and lurkign for a bit i figured i'd post a question.

I am experiencing a strange rattling sound, i thought it was grinding but it's more a vibration, when i rev the engine of my 2002 honda civic SE executive, between 2500-3200 and then at about 3700-4000 RPM.

I can only presume it is something in the engine bay that is loose and is at the point in the range is being vibrated at just the right frequency.

Im pretty sure it isn't the transmission as it happens in or out of gear with the clutch in or out. Any ideas, the best i have so far is that it could be the exhaust manifold.

 

I have the exact same problem, is it a slight buzzing that is noticeable within your range, but is especially loud and at a very specific rpm?

I jacked my car up today and had a friend stick his head under my car while I revved the engine, the sound is coming from my cat heat shield and the rust build up is buzzing at a certain frequency. If yours sounds like it's coming from the exhaust manifold area then I'd suspect its your exhaust manifold heat shield.

 

lol was just talking about heat shield issues with a coworker, who owned a 94 civic. Apparently his "local" just ripped the damn thing off.

 

I wouldn't rip it off lol

The cast manifold holds a lot more heat than a header so over long drives and during the summer it can actually heat up enough to cause paint damage on the hood. Rip it off, get a new one and give it a few nice coats of heat resistant paint to keep it from rusting out again.

 

swish! i shall do that indeed!

 

Stuck my head under the car, sounds like exhaust has come loose under there, can't see it but definately sounds like it, kind of just below the cabin, not far enough forward to be a hole in the manifold. Woop cheap fix.

 

I used to have a buzzing / rattling noise come from under the front of the passenger cabin at certain RPM's. It was caused by the heat shield for the catalytic converter. Visually, it looked okay. Using a small pry bar, I noticed that a few of the flanges where the two halves bolt together had rusted and separated.

I removed the top and bottom halves of the heat shield and have not had any issues since then.