Honda Accord Hybrid Harmonic Drone/Noise Suppression

PF_Flyer

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walzo

my car hits what i can only call a harmonic droning vibration at around 17500 rpm and also at 8000 rpm. Does anyone know what causes this... the dealer does not.

c1teach22

I have about 5500 miles on my Honda Hybrid Accord and I am also get a harmonic droning vibration. I haven't taken it to the dealer yet but this must be a common problem.

bwspoon

I am having the same problem. I have 3400 miles and it started about 1000 miles ago.

It happens at all speeds. I took it in to the dealer last week and it did not make the sound. I was frustrated when the mechanic scratched his head. This is a LOUD noise and I believe it is affecting my mileage. My gas mileage is about 20 mpg around town and 24.5 on the hwy.

It is unpredictable and happens in D and D3. It stops when I accelerate.

Today filled up before I made a 80-mile HWY trip and tripped the mile meter. No noise and my mileage was at 32.5 MPG. It started making the noise after about 60 miles the noise started and after 80 miles my average mileage is down to around 27 MPG.

Anybody else have low mileage? What are you getting?

Love the car and I want to be proud, but am embarrassed about the mileage and the noise.

It is helpful to me to see that other owners are having the same problem and encourage other readers to boost the knowledge base. I took it back to the dealer today and it made the noise with the service manager in the car. I have an appointment next Monday and will try to remember to share the results on this forum.

BARRY

Karen_S

Check Honda Accord Hybrid Owners: MPG-Real World Numbers to see what other owners are getting for MPG.

bwspoon

Okay, here is the skinny on the "harmonic drone". Evidently, as my Honda dealer tells me, I am "one of a couple" of owners (nationwide) that has a Hybrid Accord with problems with the "Anti-noise Generator". If you are going down the road when the noise starts and you open the front door and it stops, then you may be having problems with your white noise generator. The fix is to order a new set of front speakers. I am serious. If it weren’t my car I would think it was funny. I mean there is some really good comedic material here. I am going to suggest to my 16-year-old son that he rename his band "The Harmonic Drones"

Anybody else, or am I really "one of a couple"?

crystalhybrid

My new Accord Hybrid also has the drone problem. At 55 Mph with four passengers the car goes into a very loud harmonic drone. I took it to the dealer today and they were unable to diagnose the problem. I suggested that it might be the noise cancelation system and they thought I was crazy. Now that I have your experience to point to maybe they will listen. Thanks for posting.

danielsmartin

I get this too. I seriously doubt that we are "one of a couple" of people nationwide with this problem. It occurs on longer trips, especially when going downhill. In my case, it only tends to occur when the green lights are re-charging the battery, and simply shifting down to D3 or pushing on the accelerator will eliminate it temporarily. How annoying! It started doing it at around 5K miles. I worry that the mechanic won't be able to hear it or that they won't believe me, but seeing the other posts here makes me glad I'm not alone. I'm taking it in to the dealer this week and will let you know what they say. Good think I got that bumper-to-bumper warranty thing.

--Dan

:mad:

demianmac

I just got my accord hybrid back from my honda dealer. I told them a heavy bass vibration would happen at 1.5 RPM. They told me it was an interference with my 12v connection.? I am thankful I read this forum. It really looks like a lot of people are having this problem. I think Honda needs to get with it. I am tired of the "Harmonic Drones".

-Demian

crystalhybrid

My Accord Hybrid is in the shop with the harmonic drone problem. I have contacted Honda Customer care and they do not have a service bulletin on this problem and did not have a fix they could recommend. My dealer has ordered new speakers, but they have no idea if this will fix the problem. Have you had yours fixed yet (new speakers)? Is there any word from Honda on this problem? I have verified for myself that it is the noise cancellation system. When I put my finger over the front Microphone the sound gets even louder. If I open the door the sound goes away.
Thanks for any information.

crystalhybrid

The dealer just called and said they replaced the front speakers and the harmonic drone problem is fixed! I will believe it when I drive it.

midnightcowboy

Crystalhybrid,

The problem you describe is a ANC design issue. Replacing the speakers can only temporarily circument the problem; it will reoccur! When the VCM shuts down 3 cylinders it generates noise and the threshold level in the ANC system does not sufficiently attentuate the frequency spectrum, because instead of shifting the phase 180 degrees and apply the phase shift frequency to cancel noise the phase shift does not take place exactly because the speakers/microphone cannot correct reproduce the sound and instead you encounter a noise feedback loop which amplifies the part if the noise rather than cancelling it.

crystalhybrid

That is what I was afraid of. Since the microphone is not exactly where your ears are and the speakers are not exactly where the noise is generated how can the noise cancellation system work for all conditions? It seems to me that there would be nodes of positive interference throughout the car! The question is why does it work after the speakers have been replaced and is there a better long term fix? Can Honda reprogram the ANC? What I noticed is that the problem would change depending on the acoustics of the car. I.E. how many people and how much luggage etc. I have the car back with new speakers and the noise is gone for now.

s2khah

I am buying an HAH and got more information from my Honda service manager. The ANC system just addresses the exhaust resonance generated by switching to 3 cylinders since the exhaust is tuned for 6 cylinder operation.

It has a very defined frequency band pass that generates the noise cancelling output from the speakers. This resonance frequency likely occurs at several locations in the RPM spectrum although he could not say where. But likely this makes it quite insensitive to generating output caused by random noise in the car.

There are 2 microphones for this system in the passenger compartment. One visible on the center front head liner and another low the drivers side area of the rear window.

I figure that noise cancelling headphones have a good history, so Honda likely uses the best tech to do this. The cancelling uses the radio amp to run the speakers so it very well might still allow those frequencies through that are in normal output from the radio/stereo signals.

qbracken

I am having what I think to be a harmonic noise issue but is different than what I believe several people have reported. I park my HAH in a garage at home and at work so it rarely sits in the sun. But, I have noticed that only recently (past 10000 miles) if the car is out in the sun while I am out shopping or I have a long drive home that it begins to whine with a strange harmonic noise. It is difficult to describe, but it is not the low bass-like frequency some have reported. It sounds more like a whine that sometimes starts low but then becomes high pitched sounding kind of like a whale call (seriously!). This happens when I am auto-stopped, creeping along in traffic, and at highway speeds. It has happened with the A/C on and off, the brakes on and off, with the radio on and off, and with the windows up and down.

I took my car into the vendor referring to the comments on this thread regarding the ANC. The vendor called a "senior tech at corporate" to talke about the ANC problem. It is specifically to address the low rumbling harmonic and they are working with the ANC vendor and do not yet have a solution. Anyone who has had their speakers replaced have not had the problem fixed permanently.

Does anyone else who has the harmonic problem have the type of noise I described? I am at a loss and since the vendor can't find anything wrong (no surprise there) I am constantly worried it might be a safety issue.

s2khah

By description this almost sounds like something that is similar to alternator "whine". Alternator noise was a problem on earlier cars that had insufficient electrical noise filtering and resulted in a whine like noise that came through the speakers when the radio was on.
See if the noise is related to the engine speed (look at the RPM gauge) or whether the eco batteries are being charged or discharged. It gets higher in frequency with higher RPM.
Since the radio amp is on whenever the car is on (due to the ANC system) this may still be coming from the speakers even if the radio is off.
I think opening the drivers door shuts off the ANC. Don't do this while driving! See if the noise stops.
If so, it may be a problem electrical filter (or supressor) in the wiring. With age maybe a loose connection etc. Talk to Honda.

kphybrid

Cool -- now I finally know what that noise is called. I too experienced the "drone" and, of course, was believed to be insane by my service manager (not to mention that because I am a woman I was given even less credit). I actually made the service technician ride with me so I could prove the noise was happening and true to form, the car performed. Thanks for the info on this most annoying occurrence.

Clearly, there are more than "one or two" Accord Hybrid owners in the nation who have experienced (or are experiencing) this issue.

s2khah

Sorry if I misled you. But I was just describing what the cause of the sound might be, and not that I have ever experienced it (especially with my Hondas).
We have had no noise problems, or others for that matter, with my wife's 05 HAH, my daughter's 98 Civic, my other daughter's 03 Civic and my own 01 S2000 (only noises are the exhaust notes at 9000 rpm).
We have had excellent service from our Hondas and I hope yours is healthy soon too.
Good Luck.

lipitorkid

So how many owners are or aren't having this harmonic problem? This is the first thing that has caused me to re-consider buying an 05 HAH. I usually don't like to buy first year models and I believe I'm correct in thinking that the 05 HAH is the first year to employ the 3 off 6 on engine. I'm really wondering about the durability of this engine... is it the same 3 cylinders that always go off- what about uneven engine wear? And most importantly, why does Midnight Cowboy think that the problem will just come back again and again?

When I test drove the car I was impressed at how quiet it was especially at red lights. I don't want to buy a 30k car and have to crank up the radio to tune out some irratating noise.

s2khah

Couple of comments for Honda's 6 to 3 operation.
1. The HAH is not the only Honda with 6 to 3 operation. I believe the Odessy has it and perhaps other models but not sure. (A friend just returned from an 1800 mile vacation with his 6 to 3 Odessy.)
2. Many Honda engines have been equipped with V-Tec variable valve technology (upon which the 6 to 3 operation is largely based). V-Tec has been around much longer than my own 2001 S2000 has it and it is a very proven and very reliable system.
3. Honda and indeed those of many other Japanese marques, seem to produce cars which the are extensively tested before offered to the public. (My experience with owning first run (3) 240Z'z and (2) Diesel Maximas were justification for me as I put 50k+ miles per year on the cars).
I suspect that there have been many 6 to 3 Hondas sold this year and if the few complaints that have appeared in this forum are any indication, complaints may be rare.

cal_cal

I have been driving my HAH for 3 months and no harmonic noise, drones, no nothing. It's been a really good car.

ecogeek

Glad to read that others were having this problem. I called my Dealer and asked them if they had heard of the ANC issue and he told me there is a recall out for the ANC. So all you have to do is take your HAH in and a couple of hours later it's fixed!

I'll post in here when it's done and let you all know how it goes.

rhj88

If your harmonic drone sound is most apparent between 1500 and 1700 RPM try this.
1. Accord Hybrids with Navigations system: Turn the ignition switch to ACC (1) or ON (II)
2. Turn the Audio Unit off. (Radio on and Off button, push to off)
3. While holding down the upper part of both the "CH/DISK" and "SEEK/SKIP" buttons simultaneously, press the VOL/Pwr knob.
This will place it in Diagnostic mode...DIAG will appear in the upper window above the Nav unit.
Now while the engine is stopped and while in DIAG mode, turn the ANC ON and OFF by pressing the SCAN Button, you may have to push SCAN button ON and Off a couple times... While in the OFF mode, This will be displayed in the upper window above the Nav unit..... a low frequency hum (50HZ should be heard. While this low frequency tone is sounding turn the engine on and the sound should go away. IF it does your ANC is working and now is reset to the on position automatically. Now drive your car and see if the low frequency drone is gone!

If you do not have the NAV unit follow this procedure.
1. Turn the ignition switch to ACC (1) or ON (11)
2. Turn the audio unit ON.
3. While holding down both the "Preset1" and "Preset6" buttons simultaneously, press the AUDIO PWR knob.
4. "DIAG" will appear on the audio unit display to indicate you have entered the self-diagnostic mode.

NOW, while in Diag mode turn the ANC ON to OFF by pressing the #1 button, A LOW
frequency hum (50HZ) should sound for up to a minute. While this low frequency HUM is Sounding turn the engine on and the HUM should GO AWAY. Now drive your car and see if the low frequency drone has gone away!

There have been numerous cases where the ANC appears to toggle off all on its own.
My car started this drone after only 250 miles since new and with NO luck with the dealership I purchased the shop manuals which describes the above diagnostic procedure. It worked for me. Do not change the order of events. Do exactly as printed.

rockohead

I am having same problem. I am on my third Honda Dealer. They are tring to tell me this problem is normal. There is no way. I have become an expert at making the sound occur. it takes a trained foot, and a trained ear. 1500rpm is the magical number, the noise is more prevelant, on the downshift. my mileage is awful, this problem began around 1200miles. I now have 9000miles on my honda accord. Will Honda Ever live up to this?
rockohead

kmcmurtrie

I installed a decent stereo because the factory one sounds very screechy. I thought I'd need the ANC so I put in some relays to automatically switch the speakers between my new stereo and the old one. The car is quieter without ANC! There's almost no noticeable difference in the low frequencies but cutting off the factory radio eliminates a lot of white noise and door rattles.

bbyates

Sounded like a good idea and it worked for awhile but it came back the next time I started the car. I guess you would to do it every time you got in the car? I say keep the pressure on and write Honda or fax them and bug your dealer. My dealer looks me in the eye and says, "we're stumped." I don't know if incompetence is the norm now or deceit. Or both.

gagrice

I don't know if incompetence is the norm now or deceit. Or both.

I would think it is lack of training and experience with the hybrids. Training these days is short and many times just an interactive course on the Internet. Not much good for indepth training.

pacific8

Did the replacement of the speakers fix the problem ? My dealer is currently baffled ( I think they are lying) but recently I think I found the problem not the solution. Its heat related, I live in Los Angeles always above 60 car drones on a trailing throttle, usually at 40 and 60mph, drives everyone nuts, then I drove to Northern California as soon as the temperature dropped beneath 55 and it rained the car became perfect and silent, all weekend it was a delight to drive, now I have returned to LA and the drone is back. My deduction Honda in an effort to bring down the weight ( they had to do this because the batteries are heavy) they reduced the thickness of the body, that vibrates and creates the harmonic when hot, cool it down and add water and it contracts and becomes firm, no harmonic, I am off to the dealer Wednesday with my theory

smokey10

I have the same problem--it is better when it is cold and worse when it is warm. No help from the dealer or from Honda Corporate office. I'm meeting with two Investigative News teams today and they are going to do an on air report...I'm tired of the problem. I tried selling it but couldn't because of the noise!

smokey10

The dates are old on this chat but if someone searches they may have an answer... I called Honda Corporate and told them about the WBAL I Team doing a report--10 minutes later they "discover" a fix that was put out on March 24th for the loud hum problem... My dealership ordered it and it's being installed this week. Funny how I've been calling for over a year, never getting anywhere, but when a media threat hits they buckle. I'm still doing the interview with the news team--they'll follow it all the way through--including future news pieces if the fix doesn't work--which I think it won't for long... Either way, Honda sucks for not dealing with the problem immediately--I guess people being pissed about this issue cost less than the actual fix.

dmathews3

I've noticed that both Honda and Toyota are that way. That is one thing I have never had a problem with on any of my big 3 cars. They all have bent over backward to help if I had a problem.

viet

Anybody needs a (95%) new Honda accord hybrid '05 muffler please contact Qdoi@yahoo.com. Thanks.

gagrice

Viet,
You let your son talk you into one of those loud tin can mufflers on the HAH? I bet it is not very silent running now...

morphet

Thank goodness. I am no longer alone with my drone. I have owned my HAH for a year and half, noticed the droning about a year ago and then over the winter it went away. I blamed myself at first (for I know not what) since I could never actually figure out the exact conditions under which the 5 secs or so of resonating would occur. It still isn't clear to me what causes it but I do notice that with the hot weather settling in, the resonance vibrations are back and they do seem to occur on downshifting.

I read this thread of messages with great interest and am grateful to all of you who persist in calling dealers and newsmedia and making someone pay attention. I will call my dealer here in Indiana and see if they have any idea about it and get back to you.

paddy1

smokey10: I have just started experiencing the same noise with my 05 hybrid. Honda Canada knows nothing about it. Could you tell me what dealer you used to finally get the fix? I will call them and get some info.

Thanks.

steevin

Hello.

I just purchased a used HAH and did not notice the issue until I put about 260 miles on it. At first I was kicking myself, thinking I bought a lemon. I'm glad to hear others have the issue as well.

I agree with some of the other posts. Heat does seem to be a factor with this issue.

Has anyone had the ANG replaced by the dealer? Did that fix the issue? I bought my vehicle out of state, so returning to the dealer of purchase is not an option for me. I would like to go to my local Honda dealer with a definitive answer as to what fixes this so they can proceed appropriately.

Thanks,
Steve

paddy1

After hearing all of Smokey's problems, I decided to call a dealer in a major US city. (I'm in Canada) This of course was after calling both Honda US and Honda Canada, both of whom flat out denied this ANC problem existed. The service manager was very helpful (mine won't even discuss it until I bring the car in.) He looked up the problem in the TSB database and came back with TSB 05-006A.(it might be 06-005A, as I wrote it down at work today). If the booming noise is observed by the dealer, the ANG should be replaced along with the front speakers, as they are tied together. I seached the web and found the actual TSB document by Honda on Alldata.com. I am a little worried about getting the dealer to hear the problem, as with my luck it won't happen. I do agree that heat is a problem, as this week in Ottawa it has been around 30C and it happened on each use. I still don't know how both Honda Us and Honda Canada can deny the problem exists when there is a TSB out on it. Pathetic. It's still a great car. Does anyone who has had it changed have any advice for getting the dealer to A)hear it happening and B)Agree to change it...Thanks

nocapisce

I had an annoying drone harmonic on my 2004 Civic Hybrid. I chased it down to the black plastic trim on the lower left side of my windshield. I stuck a piece of reinforced package strapping tape there and problem was solved.

The sound/drone was as if it was the transmission or front lefttire or engine compartment/wheel well. The tape came loose but stayed on the black trim. This tape just sitting there was enough to break up the harmonic. Think reed in a wind instrument

nocapisce

morphet

Update on the Indiana HAH with drone - my dealer looked it up in his Honda materials and suggested the replacement of ANC and front speakers solution. Seems rather extensive. I couldn't tell from reading this string of emails whether anyone had had complete success with the full ANC (or in Canada, ANG) replacement? Next step, I have to bring it in and hope that it is warm enough for a drone to occur and they can officially diagnose a faulty ANC. I am assuming that this replacement is gratis but I haven't got that far yet. I have thought of just sticking a magnet somewhere just to see if that little bit extra something changes the standing wave frequency enough to stop the resonating a la the tape on the plastic trim. And, I am going to try the self diagnostic trick sent in by rhj88 on Sep 17, 2005.
Keep you posted on any future successes. In the meantime, it's happy droning... I mean driving.

dmcse

I am glad i read some of the articles re the "Harmonic drone". I have had this problem for some time but, I am pretty convinced that it's more prevalent in hot weather. Having taken the car to the dealership twice, the Service Manager reiterated that this was normal. I took it up with Customer care at Honda Canada, and he immediately spoke with the Service manager, and came back to me and conveyed to me that there is a problem with the Noise reduction System and that I would have to take it back to replace this system. i am taking it back on Monday, and will keep you informed as to what happens. In the meantime... enjoy the Torture Chamber

rhj88

Remember when going through the diagnostic that you do not want to use the program to turn on the ANC as that will actually disable it....follow the instructions I posted exactly and when you exit diagnostics the ANC will be on.

My dealer is in Lodi, Calif. and I demonstrated this to them on a test drive with the district parts and service manager in my car. They were surprised to say the least because at first they thought I was crazy! They were supposed to enter it on their dealer network computer links for all dealers to see.

dmcse

Exasperated, I called Honda canada customer service. the techie was very helpful, and did know abou this problem. He called the service manager at my dealership and told him what to do, and requested me to take the car in for tests. They kept the car for 2 days, and replaced the front speakers and the Noise cancellation System. I got the car back yesterday, and up to now no drones so far... Thank God!!. I hope it doesn't recur. So there you have it folks.... Good luck

pfcannis

How much did it cost to have the issue resolved?

pfcannis

That seemed to work some but it still comes back. Have you had the problem fixed yet??

cagriz

I have had this problem since March (warmer weather) and I can't get them to fix it. People I drive know about it and won't ride in the car. My dealership says they don't know about it but the guy who does the work in the dealership is an old friend and he said he's been looking. Do you have or know what the fix from the March 24th actually does? I need to get this fixed as soon as possible - it's driving everyone crazy!

txchristopher

I thought this was a dead issue. My Accord Hybrid was the very first to develop this drone and completely baffled my Honda Service department. They tried everything, even pulled a new one off the lot for parts switching. Replacing the speakers, the microphones, the radio head unit, and even the ANC itself will NOT fix the problem. Neither will replacing the active motor mounts. My service department spent thousands on my car and over 60 billable hours labor. They had the car 35 days straight.

I raised mega flak with Honda over this and threatened lawsuits as well as big media coverage here in Houston. Honda flew in an engineer who's job it became to fix my car. He analyzed the problem and I was told he downloaded software and expanded the range of the ANC to cover the drone, it is in a frequency outside the original envelope of the as designed system. I have the paperwork at home somewhere.

Using what they learned from my car, I was told that they developed a fix and incorporated it into the line. Several months later I got a call from my service guy telling me to bring my car in for the permanent fix, that mine was just temporary. Well, with over 150,000 miles of no drone whatsoever, I think I will keep my "temporary" fix.

Whatever is the cause and whatever the true fix is, it must be pricey because they have known about it since March of 2005 and a fix does exist, I am proof. That they are not fixing the cars is disappointing.

Let me know if I can be of help.

.

cagriz

I did receive the ANC fix after showing the service dept at my local dealership this thread. Now that the the massive drone is gone (also colder weather) there is still this slight drone that is irritating as well.

I'm thankful the major noise is gone (8 weeks for the part) but that noise is still there and I can't say it's as loud but I know it's still there. Is this what you found as well?

I'm looking at another hybrid at this time since this seems so sporatic.....

I'm not angry yet but I'm getting there!! I'm just really disappointed in Honda....

txchristopher

I never experienced any droning again at all after the fix. I have a slight low level vibration when the engine is lugged in eco mode at 2000 - 2200 rpm or so, between 66mph and 72mph works well, just barely touching the throttle and when it falls to eco mode the vibration is there. I do not think it is related to the drone at all though. Really any rpm below 2200 where the car is at very light throttle and eco comes in nets the low level vibration. 55 mph is probably its peak of intensity though.

My Accord Hybrid has led a very hard, rough life, and to be honest I am suprised it has taken the abuse as well as it has. I promise you I have found the weak points of the car.

.

viet

My Accord hybrid '05 had oil leak at 12K miles and was fixed (at $10K cost) by the dealer. Now, the "humming noise" is getting worse probably when switching from gas to electric engine according to my son who has driven it the most. I brought it back to Honda dealer 2 months ago and they deflated 4 tires down to 32 PSI and said "no problem at all". I am going to bring it back to the dealer next week. Do you have any suggestion? Thanks.

gagrice

Where have you been? I wondered how you and the Accord were getting along. So do you still think Honda engineers are the best in the world? Are you going to buy another Hybrid or go back to the Accords that gave you great service? All the Accord hybrids seem to suffer from the droning problem. May be why they are not selling well.

viet

Hi Gagrice:

I have been here browsing these forums once in a while but no more messages to read or comment. I did not hear much of the droning out of my Accord hybrid. But my son does. I asked my son to drive it to a Honda dealer near his college campus to fix it but he insisted to drive it back home for checkout. Now, I drive the second oldest Accord V6 EX 2002 in my household. Yet, it's smooth and gives me plenty of power. Poor Dad !

Also, do you know how to duplicate or order a Chapman basic remote car alarm control? I lost 1 and have only one control as a spare. Happy Thanksgiving to you and yours.