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Hyundai Sonata Rear Thump

silverfox1silverfox1 Member Posts: 91
edited March 2014 in Hyundai
Have a 06 Sonata LX. Chasing above average rear body/ chassis thumping when going over a bump or step in the pavement. Have relocated the spare and tighten the holding mount. Re adjusted the two trunk stops. Securing the spare helped but still have some thumping. Is it possible that some added padding to the trunk floor will help? Anyone have the same problem and a solution?


  • stockmanjoestockmanjoe Member Posts: 353

    I have a 2006 Sonata GLS 4 cyl. I hear a slight knock or bang (I think coming from the undercarriage) often times when I first accelerate. Does anyone else have this?
  • tb88tb88 Member Posts: 242
    May be it's the fuel used causing knocks!
    Switching to a different gas station / higher octane may solve the problem... Old gas stations sometimes have storage tank problems (water/contamination...).
    I always try to get Gas at the newest gas station around.
    I also read, that some new 4cyl cars require Premium (i think i read that in a Civic Si review!!
  • silverfox1silverfox1 Member Posts: 91
    No problems with noise from chassis or body on take off. Thumping occurs when driving on bumpy roads. Car is very quite on smooth roads. 17" tires do not help the thumping issue since they have very little give to them. I think added insulation and better quality bushings between the chassis and body would help. Anyone out there have any thoughts on this problem?
  • stockmanjoestockmanjoe Member Posts: 353
    Thanks tb88 for the reply. Don't tell me that - last thing I need to do is buy premium gas. Hopefully it will stop.
  • hmma007hmma007 Member Posts: 19
    Hi Silverfox, is the noise definately coming from the spare tire well or is it from one of the rear wheel wells? Just curious,
  • silverfox1silverfox1 Member Posts: 91
    Sounds seems to come from the lower trunk area which makes me think the suspension is not isolated enough from the lower body. Car is so quiet on smooth pavement any noise is offensive. Will review issue with dealer some time in the future. Do you have a similar condition?
  • cxccxc Member Posts: 122
    I noticed similar condition for my 06 Sonata LX. It turned out that the fold down rear seats were not locked as the car came out the factory. After locking the rear seats from trunk, I did not hear any abnormal sounds from the rear. I hope this will help.
  • silverfox1silverfox1 Member Posts: 91
    Thanks for that info, will check that out in the morning. I been playing mind games trying to figure out what and where it is coming from. I was thinking of the exhaust system as it seems more pronounced when the car is cold but may be my imagination.
  • hmma007hmma007 Member Posts: 19
    Silverfox1, I work for Hyundai in quality control. I'm not here in an official capacity though (hence the 007)

    If I understand you correctly the noise is coming from the rear suspension when you go over a sharp bump or step? Sounds like rear hub noise to me. Tell your dealer service that you suspect you have rear hub noise and that you may need your e-brakes adjusted. At least sitting here that may be the issue.
  • silverfox1silverfox1 Member Posts: 91
    Thanks for the reply. I have an Sonata LX with rear disks. I believe I may have found some of the problem. I think the cover for the spare moves vertically and may have a drum affect. I went over a sharp bump yesterday (rail road tracks) and it sounded like came from that area. I had repositioned the spare and tighten the holding hardware for the spare earlier so I know that area is secure. I also have locked the rear seat backs from the truck. Will try to secure the spare cover (trunk floor cover)to see if that has any improvement on the drumming.
  • hmma007hmma007 Member Posts: 19
    Hmmmmm that's odd that there's noise from the spare tire cover. I won't say what part of QC I work in because that would narrow me down too far, but I've never heard that as an issue. I'll keep a lookout for that in the future. I know this sounds silly, but is the spare tire cover turn the right way (litle pull handle at the rear) and is the trunk liner pulled over the rear seat "flaps"?

    Hyundai road tests all cars thoroughly for noises, quality and safety issues.
  • silverfox1silverfox1 Member Posts: 91
    Just checked my trunk and see that the trunk cover is over the rear seat cover. Also the spare cover is correct with the tab to the rear. Interesting that the two rectangular slots that accept the spare cover tabs (two) do not have any means to latch or hold the cover in place. Should there be some type of clip mounted on the rectangular slots to catch these tabs?
  • silverfox1silverfox1 Member Posts: 91
    Still fighting this excessive thumping noise when going over bumps on my 06 LX. Starting to think that the oversize trunk resonates with the suspension on bumps. Any thoughts on that theory?
  • tb88tb88 Member Posts: 242
    All you have to do to find out is to fill up the trunk with something, preferably with something that wouldn't bounce and make noise: Blankets/pillows/foam/ etc...
  • hsonata06hsonata06 Member Posts: 4
    I recently purchased the '06 Sonata LX, and I am experiencing the same rattle/rumble thumping noise in the rear passenger hub area!!!!

    The service department said everything was working to Hyundai specs (they had a "Hyundai engineer" test drive it with me and he said it was normal road noise - baloney), and the general manager said he is trying to get Hyundai to address the issue, but to no avail.

    It occurs on bumps and dips usually below 30 mph. It is especially loud under 5 mph when you go over a bump or dip.

    There is also a constant droning/resonating hum noise when the car hits about 30 mph and higher, which is most noticeable on concrete.
  • silverfox1silverfox1 Member Posts: 91
    I have looked into several approaches to reduce the rear suspension noise starting with the most cost effective one first. I purchased some top of the line carpet padding and placed it between the trunk carpet and the body pan. This helped with reducing some of the high frequency noise and some what reducing the rubble sounds. The better solution is to invest in the rubber/alumium wrapper material that the audio people use to reduce the resonance when installing those large base speaker systems. I checked into it and a 12 foot square of this material was $96!!!!!!!!!! To do it right you should do the trunk and rear floor area's. Not ready to spend this kind of money to cover a design problem. On the concrete noise issue, "haefr" is right on the money. It certainly is a tire tread issue. I have a new interchange near me and those Michelin Pilot tires do make noise on it. My Continentals on my old VW GTI did the same thing. Let me know if you get and help from dealer on the rumble issue.
  • lastwraithlastwraith Member Posts: 350
    If you want to try something on the trunk of the Sonata to reduce the noise level and don't want to shell out for Dynamat, BrownBread, etc try some Ice Guard or similar material at your local Home Depot or wherever. It's made for weatherproofing/insulating your roof but it makes a pretty good soundproofing material and you can't beat the price or availability. I use it in place of Dynamat and the rest for certain installs.

  • stealth6stealth6 Member Posts: 13
    Try tightening down the spare tire. I mean really tighten it down!
  • mamamia2mamamia2 Member Posts: 707
    The "thumping" noise, known elsewehere as K-Thunk is a problem of the V6 models only, and seems like it is typical to the '06 model cars only, and apparently was fixed in the '07 cars.

    The latest info published, unofficially though, is that the cause of the noise is the REAR SUSPENSION, and that Hyundai is now working on a fix that's suppose to be in the shape of a RUBBER seal that needs to be added to the rear shocks. Stay tuned.
  • vmokhutovvmokhutov Member Posts: 23
    Hello happy owners of sonata. I am thinking of buying sonata 4 cyl. with manual transmission and I'd like to ask you how good and reliable this transmission from your experience. How easy it operates, how you like the clutch performance, what engine rpms you have at 120 km/h. and how quiet a car at this speed. Thank you for any info on these questions. Enjoy your cars
  • hdsithdsit Member Posts: 58
    Se latest post on this thread:
    Could this be the solution for the sonata's k-thunk problem too? - If they share components.
    also from :

    "Well I just took my Azera out for a drive and the noise is completely gone. It was great I did not feel like I had to dodge every pavement irregularity My dealer, Green Hyundai is located in Springfield, IL. The part number for the struts are 54611-3K050 and the insulator assemblies are 54630-3K000. I hope this helps, it sure did the trick on mine. "
  • silverfox1silverfox1 Member Posts: 91
    Just sent Email to Hyundai using their web site. Asked them to respond to Azera fix for k-thunk problem for my 06 Sonata LX V6. Will post their responce.
  • johnwintxjohnwintx Member Posts: 7
    I've had 3 Sonatas since Feb '06. My first was a GLS V6 which I traded in July '06 for a GL I4 5-spd man due to disappointing miles per gallon averages with the GLS V6 (5-spd auto). I realized a whopping 1.5-mi average increase in MPG. My new Sonata is an '07 Limited. I'm getting about the same MPG as I got with the first Sonata, and I'm delighted with the accessories in the Limited. My advice: if you're going to get a Sonata, get the Limited. I got mine for $22,559 less a $2,500 total cash back for a nice $20,009 (plus TTL).
  • ray_h1ray_h1 Member Posts: 1,134
    )) "http://townhall-talk.edmunds.com/direct/view/.f0f43c4" ((

    That URL only addresses front end clunking noises in the Azera.
  • ray_h1ray_h1 Member Posts: 1,134
    I wonder whether poster vmokhutov is a Russian citizen... (Hyundai cars are distributed in Russia, but I question whether the automaker has its own import arm in that country or deals secondarily through a Russian import agency. Regardless, it would be anyone's guess whether the automaker makes available the same promotional rebate considerations in other world markets we enjoy in the U.S.)
  • spudwitchspudwitch Member Posts: 1
    Hello everyone....I'm new to the posting thing and wanted to let you know I have just purchased a new 2007 Sonata Limited V6 and I too have the K-thunk going on. I have noticed it only when I first start it up and accelerate. It doesn't matter how cold or hot the weather has been outside or the number of days it's been setting......it ONLY happens when I pull out of my driveway.......maybe it's a cold engine thing???
  • guestguest Member Posts: 770
    Spudman... What you have described sounds like the ABS Self check test that occurs when you first start & engage the Car. Its in the manual :)
  • ray_h1ray_h1 Member Posts: 1,134
    Exactly what "unknown" said. Your noise occurs during the first acceleration after an engine start at ~18 mph. You may even feel some feedback through the accelerator pedal simultaneously. It's all perfectly normal - your car's simply communicating with you that the ABS is functional.
  • kimsheekimshee Member Posts: 4
    Just bought an 07 LX V6 here in Austin with loud, thunkin rear (& front in my opinion) suspension. Have had the strut mounts replaced, everything "loosened and retightened to specs". They are still scratchin their heads. The noise level is unacceptable and I will push to return the vehicle until it is fixed (already 1K on the car). I've given them all info on this site. Great car - except the rear suspesion noise. Continuing to push them to go to Hyndai direct - will wait this out until I am their worst nightmare...close though to goin and getting a new Camry. :lemon: Silverfox - keep in touch with ifne041 at y dot com.
  • miamixtmiamixt Member Posts: 600
    Sorry to read about this problem on your 2007 LX. I read they didn't make those anymore?. Almost 2000 miles on my 2006 Limited,, and it gets better everyday!. Plus no Thunk Thanks :)

    NO :lemon: Pure Pleasure. The Award Winning new Hyundai Sonata. Take the Hyundai Challenge :shades:
  • drdonrsdrdonrs Member Posts: 164
    I have posted this email letter over on the Azera board and over at Edmunds. When I hear I will post any response I get.

    Here is a copy of my email just sent to Hyundai Consumer Affairs. I will post any response as soon as I get one. I will be following up with a phone call.

    I am the owner of two(2) 2006 Hyundai vehicles purchased during the past 9 months from Hyundai of Westchester in Yonkers, NY. I own a Sonata LX (3500 miles) and an Azera Limited (1600 miles).
    I am sure that you are aware of the Azera's front suspension noise and the Sonata's rear suspension noise. I am an active participant on the Hyundai-Forum's board and the Edmund's board. There are many disgruntled owners of these cars because of the apparent suspension "defects". Firstly you must understand that I have been a strong advocate for the 2 vehicles that I own and have even offered to act as a "good will ambassador" so to speak for my dealer's prospective Azera customers, as a very savvy and satisfied customer, so to speak, so I don't send this communication in an adversarial capacity. You should be aware that there are owners, of Azeras in particular, who are about ready to expand their dissatisfaction with going so far as recommending a class action lawsuit.
    In any case I am certain that Hyundai is most intent in emphasizing the quality and value of its product, because I see the references to the JD Power Initial Quality awards. of which Hyundai vehicles are high up on the list, and which are prominently displayed in the dealer showrooms and in the media.
    All of the owners are certain that you know this problem exists and all are awaiting your acknowledgement of this instead of the apparent silence that has enveloped this major customer concern. Many of us have had acknowledgement from service managers at the dealerships and even from regional tech reps but no word from "above".
    Please, in the interest of keeping the owners of your top of the line vehicles happy and contented, I would urge you to at least acknowledge this communication and indicate that your engineers are at work to effect a "fix" for this problem. As you may be aware that almost all of us who are Azera owners and Sonata owners absolutely are enamored of these cars, so please don't destroy what can become a long-term relationship.
    I do expect to hear from you in a timely fashion so that I can post the answer on the message boards so that you can avoid a massive disenchantment with 2 very fine cars, Azera and Sonata.

    Donald Scharoff
  • ed_ged_g Member Posts: 16
    Hi Donald,

    I hope you get a response that says a fix is coming. I do
    not want to have to trade in the car. I know Hyundai had a bad reputation years ago and I decided to give them a try now, but I am not happy with that annoying noise. Can't believe I missed that noise during the test drive.

  • ray_h1ray_h1 Member Posts: 1,134
    '03 Sonata GL V6, with 22,400 miles here. Not my first choice after totaling my '96 Accord, but, A), it's paid for, and B), no clunking... The more late posts I read about the new generation Sonata and the recently intro'd Azera, the more I'm thinking Hyundai could've spent another year R&D'ing their engineering and assembly. Like cousins who marry, inevitably, accelerated R&D cycles are not a good thing with complex systems. (New design, new engine, new, highly automated, offshore factory and an alien workforce with unexpected tolerance for Hyundai's workforce culture in the States - a recipe for "interesting times" for the Korean automaker used to its regimented, acquiescent labor force on the home shores.) Late '08 will be my next automobile decision year. Hyundai's still on my list - just not my tentative short list.
  • comet64comet64 Member Posts: 12
    Thanks for taking the lead on this problem. I can't add anything additional to what you have said. I hope that the Hyundai Consumer Affairs people monitor this site and realize that this is a widespread problem and not isolated. I think that most of us would be satisfied temporarily if Hyundai would acknowledge to the owners that they are addressing the issue. I can't believe the rear suspension noise would be much of an engineering challenge, but it might be more of a financial issue.
  • silverfox1silverfox1 Member Posts: 91
    Just sent my second Email to Hyundai on the rear suspension noise issue. Will stay the course until they respond. Love the car but would like to get an answer on this.
  • miamixtmiamixt Member Posts: 600
    Hyundai sells Cars in 86 Countries. I doubt they have readers scouting consumer web sites for problems. As the highly acclaimed Mamamia has noticed, the I4s don't Thunk?.

    Perhaps it is the dual exhaust pipes. I know mine feel loose, however thankfully I have no Thunk!
  • drdonrsdrdonrs Member Posts: 164
    Here is a copy of my latest posting over on the Azera board. I am also going to post this over at Hyundai Forums.

    75 of 75 Re: The Dreaded Clunk [roadkingtc88] by drdonrs Oct 25, 2006 (3:13 pm)
    Bookmark | Reply | Edit | Delete | E-mail Msg
    Replying to: roadkingtc88 (Oct 25, 2006 11:17 am)

    As I have suggested, the moderators of this board as well as the Hyundai Forums should put together an electronic petition that all of us can sign indicating our displeasure with the lack of response and acknowledgment on the part of Hyundai USA. By hinting a joint action I do believe that we will get their attention. It might not be a bad idea to indicate that we, jointly, will be in touch with the automotive publications as well as Consumer Reports. It is necessary to show that there is joint concern and that it could trigger a joint negative reaction that will not serve Hyundai well
  • kimsheekimshee Member Posts: 4
    Good news my friends,

    My dealer informed me Hyundai has released an official fix kit that includes new struts and mounts. The service mgr learned of the "unbroadcast" fix and had to have the regional manager approve the request and delivery. Apparently Hyundai has not yet released the fix but somehow is releasing it under certain conditions (?). They received the "kit" today and are just as curious as we are - they did say it appears to be an official "kit", not just some parts. The service mgr reported that this is a problem on Sonatas mfr before Sep 06 - look on your driver door jam. The car should be ready tomorrow. I will milk him for all info possible and post here later in the week. Hopin this is it!
  • ed_ged_g Member Posts: 16
    What is the email you are using to contact Hyundai?

  • ed_ged_g Member Posts: 16

    I should have said the question was for #33.

    Hyundai Consumer Affairs

  • kimsheekimshee Member Posts: 4
    Given my experience it is more effective to leverage your local dealer for influence and voice to Hyundai. I made it clear from the get-go that my car is defective and I wanted Hyundai consulted directly regarding the rear suspension noise. A few (or group of) unhappy customers are not on Hyundai's radar - volume ranking, stateside dealerships are. It is all about the bottom dollar; until sales and repair costs indicate a problem, any mfr is unlikely to respond.
  • ed_ged_g Member Posts: 16
    I will do that. Once you find out the kit works please post the kit number or information you can about this "unbroadcast" fix.

    Thanks for your help.

  • franmartfranmart Member Posts: 16
    was the date you had sept 6 2006 or 2005 thank you :lemon:
  • ed_ged_g Member Posts: 16
    My car was manufactured 7/20/06

    Talked with Hyundai Customer Affairs office today. They know of the problem in the 2006 model, but I was the first to complain with a 2007 model. They have no plans to fix it as of now because it is not a safety issue.

    They told me to have the dealer put the car on a lift and check it out to make sure it is nothing else other then the familiar thumping. They told me to keep pursuing it and they could end up fixing it some day. Anything is possible. It is hard to believe they keep manufacturing the same problem into next year model which I bought. I guess they are consistant.

    I went under my car. One thing I did notice was the stabilizer is made from a thin steel. My other cars have much heaftier steel. Wonder if that could be it. They cut the size to make it cheaper.

    Ed G
  • miamixtmiamixt Member Posts: 600
    Your conversation seems somewhat suspicious?. So they knew of this "problem" with the 06, but decided to produce the 07's with the same noise anyway?. Does anyone believe that they reworked the Sonata for the 07 Model year?. No, it is the exact Car, with the same parts. My 06 LX (born 08/19/05) turned 2000 miles today, and tomorrow I turn 48. Thankfully No Thunk in the Trunk! :shades:
  • kimsheekimshee Member Posts: 4
    2007 models mfr before Sep 06. Miami - be suspicious if need be, I'm just relating the facts and am making no assumptions as to what has occured year to year.

    Picked up my car today with the newly installed "kit". Definately a stiffer response through the wheel. The rear seems to be quieter, but my preliminary feeling is only a 50% improvement. I do notice more front suspension noise, probably revealed by the quieter back end! Will drive more this weekend and give a conclusive response. No parts # yet, the Service Mgr said it was suppose to "not be released". Believe it or not, take it for what it is worth. Will post more later. :confuse:
  • ed_ged_g Member Posts: 16
    Thanks for your feedback. Hope it does show to be better.

    I am surprise too that if they knew the problem was in the 2006 why it wasn't fixed in the 2007 model. Unless the real fix would have reduced their profits enough to not bother.

    Let's just wait and see how you feel about it.

    Thanks again,
  • silverfox1silverfox1 Member Posts: 91
    Glad to hear some positive results on the kit installation. Will continue to monitor this site for further info. Could you supply your dealer and his location? Also were the front struts and mounts part of this kit or just the rear only?
  • ed_ged_g Member Posts: 16

    I noticed yesterday I had a car full of luggage and 5 passengers. It sounded like I would expect. Much better.
    Maybe the shocks are too stiff. It may be a matter of putting in some better shocks. No one makes them for a 2007 yet.

    Ed G
  • ed_ged_g Member Posts: 16
    How is the fix doing so far?

    Ed G
This discussion has been closed.