Horrible 2006 HAH chattering noise
 

My father owns a 2006 Accord Hybrid. The car averages about 21 MPG. He drives almost 100% short trips around town so perhaps this explains the poor millage, however, he could probably get better millage out of a conventional small SUV.

However this is not the main problem. The main problem is that when driving on some road surfaces at certain speeds, the car makes a sort of "chattering" sound that hits resonance and becomes incredibly hard on the ears. Therefore, on just the right road surface at just the right speed, the whole car resonates with this loud rumble.

Has anyone else experienced this problem?

Re: Horrible 2006 HAH chattering noise
 

Wow, that is pretty poor FE but I suppose if the trips are REAL short, the engine barely gets warmed up (where ECO mode will begin activating). I can usually get between 29 and 32 in town with my 2007. Ask him if he sees a fairly active CHRG and ASSIST when he drives (this is also impacted by temp).

I'm not sure what's going on with the resonance road noise problem. I haven't experienced that and it makes me think something in the drivetrain system could be having a problem (might also be related to the fairly low FE). Has your dad taken the car in to be inspected?

Re: Horrible 2006 HAH chattering noise
 

I have spent some time driving it and it does spend a good amount of time in ECO mode and the CHRG and ASSIST remain fairly active.

The noise resonance is really weird and my father did take it in to a local mechanic who was unable to identify the problem. I had said earlier that the car was a 2006 but it is in fact a 2005. My father had signed up for the waiting list in early 2004 before the car was out and was among the first owners of the car in late 2004. Therefore, it is out of warranty, at least with respect to the non-hybrid systems, so my father is a little reluctant to take the car in, as in this area, any trip to the dealership can result in a bill for thousands of dollars with no guarantee of a successful outcome.

I also though that the noise might be tire noise, but I no longer think that because sometimes the noise occurs when the car is moving very slow, but usually it occurs when the car is just under 40 MPH, although it is not consistent. The sound appears to be coming from the middle of the car, although it is hard to tell. Once the noise starts to resonate, the whole car pulses with this sound.

Re: Horrible 2006 HAH chattering noise
 

Re: Horrible 2006 HAH chattering noise
 

Thanks, that's my answer!

-Joe

Re: Horrible 2006 HAH chattering noise
 

I had the same problem and thought I had engine or transmission problem.
I had it to dealer multiple times over a course of one year to find the cause of the problem.
All IMA engines have an anti-vibration device as part of the system and it is located in your front speakers. I kid you not!!
Even if you take your Accord Hybrid to the dealer for repair, most likely the mechanic will not identify the problem. If the mechanic has not experienced this repair, they will not find it.
My repair was covered by the Honda Care I purchased when buying the car, but should have been cover by the standard warranty.
I hope my experience will help you all having the similar vibration problem.

Regards,
Mike

Re: Horrible 2006 HAH chattering noise
 

Well try as he did, my father could not get the Honda dealership to discover the problem. We informed them about what we learned on this forum, and even presented them with the service bulletin, but all they would say is, "thats not it." As the car is not under warranty it would cost too much to keep bringing it in to let these guys hunt for something that is obviously beyond their ability to repair. The time has come to sell the car, I don't know how much he will get for it at trade in given the fact that it makes this noise and because it has been in an accident. I think his next car may be a Ford Fusion Hybrid.

Re: Horrible 2006 HAH chattering noise
 

Does the car have ANC (auto noise cancellation)? IIRC, the HAH has VCM (runs as a 3 cylinder), which is typically combined with VCM. The sound you describe sounds like a failed ANC system, when the engine goes into the VCM mode and creates a buzz/rattle. Did the stereo fail, or did anyone 'upgrade' the stock stereo?

Re: Horrible 2006 HAH chattering noise
 

When in eco I've put my thumb over the microphone for the noise cancellation (on the headliner close to the sunglasses holder). It is amazing how noisy the cabin gets. If that did not work right, I could see how annoying this car would be.