Ever since the local Acura dealer did my timing belt and water pump, my Accord has been buzzy. The dealer claimed they did nothing wrong, and wanted $600 for a new A-pipe. I put one in myself for $300 and change, and just as i suspected, it's still buzzy. I have one more exhaust seal to replace (B-pipe to cat), but I really don't think that's the problem. Lots of trim bits start buzzing at high revs, and the car just isn't the pleasant touring sedan (maybe a stretch) that it used to be.

Anyone know if the balance shafts have to be "timed" to the engine? And whether if they're not in proper time, they'd increase the engine's vibration? Only other thing I can think of is a bad engine mount. I'd really appreciate any insight. A second dealer (Honda, this time) didn't seem to understand the problem. These guys can't seem to hire competent people...

Thanks!

 

Need more info. Can you zero-in on where the vibration originates?
If, during the timing belt install, they slipped a tooth or two on your balence shafts I'd think the out-of-synch rotating mass intened to quell 4th order vibrations would cause worse symptoms than you're feeling.

 

Thanks!

There are two symptoms. First is a slight resonance in the A-pipe at maybe 2250. Seems like the A-pip is the culprit, because you can stick a wrench under there and apply a bit of leverage to stop the noise. But since a brand new one (and attendant seals) does the same thing as the old one. I just don't buy that the new A-pipe is somehow defective, especially since the problem started when I picked the car up from getting the timing belt done.

The second symptom is that above 3500 RPM (I spend a fair amount of time up there), interior plastics start to buzz in tune with the engine. I can't tell much from under the car at high revs, but in the car, it's awful. That made me think about vibration sources. Maybe they installed the balance shafts wrong, maybe the engine mount on that side is improperly assembled, etc... I did find that one of the shields on the body near the cat was crinkled up, so I straightened that out. But no contact I can discern between the exhaust and the unibody.

That's about all I've got to offer right now. The Honda dealer yesterday managed to add a full throttle resonance that sounds like exhaust escaping at full throttle. So I do need to try changing the B-pipe/cat seal this weekend. But both an engine mount and a balance shaft timing problem are out of my league of shade-tree stuff.

That add anything pertinent? Thanks again!

 

Follow-up: Looked under the hood this morning and the Honda dealer yesterday neglected to reconnect my intake snorkel to the throttle body. How nice... I put it back on, so the full throttle thing is gone again (and that was an intake suck sound, obviously, not an exhaust hole), but the resonance down low and interior buzzing up high is the same as it was.

BTW, what is up with these dealers that they can't fix a car with any degree of care?

 

Modified by CardDealer at 4:19 AM 11/16/2006

 

The 2250 rpm buzz is caused from the 2 gaskets between the apipe and converter- honda makes what they call a "buzz kit" to fix this. It comes with 2 donut gaskets, 4 springs and 4 new bolts. Im assuming you have a 94-97 accord.


[Modified by fixhondas, 3:16 PM 9/1/2001]

 

Thanks for the tip!