Help! lol So I've been having buzzing sounds for a while now from my Accord 4cyl. They happen at 1800 and 2400 RPM and at highway speeds. I'm not sure if this is a common problem. I changed the mid-pipe exhaust gaskets and hardware. That didn't really fix the problem. I then noticed the two bolts from the "front" pipe bracket that go into the block were missing and thinking I put the wrong bolts in. The thread was right but they are studs with a nut(manifold bolts). I plan on removing them tomorrow because they only made the car vibrate when warming up and the buzzing worse. I've also been told about buzz kit but not sure what that is. I didn't hear anything in the catalytic converter when I knocked on it. Any information you have wold be great, thanks!

- Tyler, NJ

 

Loose heatshields?

What "mid-pipe" did you change? Or change only the gaskets & hardware?

Certain years (not sure which) the A-pipe is a double-wall pipe, and the inner pipe buzzes against the outer pipe.

 

Yeah I actually have no heat shields because they/it broke off. I changed gaskets and hardware on the mid-pipe in front of the cat. I've heard of the double-wall pipe. Any idea how to find that out or just Google? Thanks!

 

The A-pipe is the one going under the oil-pan, and you can see the inner & outer pipe if you open it up & look into the back end of that pipe.

If you've really truly ruled out other rattles, that leaves the buzzing pipe. Unsure whether that pipe is double-wall for your year, maybe you can talk the dealer parts-counter-guy to let you look at one??

The inner pipe is attached to the outer somewhere towards the front end. If the inner or outer pipe gets bent or even warped with age & heat, then towards the back they get too close to each other.

 

yeah the a pipe has the bracket with two bolt holes into the block. my oil pan seems to be rusted above the a-pipe and also around the mounting bolts. It's only surface rust but I probably shouldn't take any chances. I guess it's time for a new one. I also noticed that when I was changing my oil earlier that the rubber on the front motor mount was cracked and separated. I have a feeling that might be part of the issue too...

 

Cracked front motor mount can contribute. When accelerating, the front mount tries to lift upwards, so a broken mount can allow it to move more than it's supposed to. That puts more "flex" in the exhaust system, which has to be taken up by flexible joints.

I just looked at a parts drawing, for 96 LX 4-door auto-trans (you don't say what yours is). There's a flexible joint with a donut-gasket and spring-loaded bolts just right next to the mounting bracket. If that joint can't pivot far enough to allow the extra motion of the engine, then it's gonna bend something.

 

My apologies, it's the automatic. Noticed the motor mount definitely moving when I accelerated to about 2000 rpm with my foot on my break and the car in drive. Front motor mount is definitely cracked. The mount on the drivers side seems to be bad as well but not entirely sure. I hear a noise at idle and it's coming from that area. When I shut the car off, I grabbed the drivers side motor mount and moved it as much as possible I'm thinking that could be the problem. I should record the sound and post it oops