Hyundai Sonata Engine Questions

jbhomejbhome Member Posts: 1
edited March 2014 in Hyundai
I am looking at a 2004 Sonata with 41000Km/24000Mi. The car is immaculate but... When in drive and stopped, engine noise/body vibration is significant. I'm told they are all like this, however...
My 2000 Ford Focus has similar problems which started several years into ownership and got worse. When cold, the dash vibrated, coins rattled in the cup holder. In 2006, I finally bit the bullet and replaced the engine mounts. Voila, new quiet car. An unbelievable change. So now back to the Hyundai. I think it also has fluid filled engine mounts. Is this the cause? Service says it's rough because of the counterballancer but this should make it better.
Anyone have any experience with this problem.
Jim Brooks


  • donx1donx1 Member Posts: 2
    My 2006 V6 Sonata is two weeks old and has 300 miles on it. If I accelerate to say 30 mph, and then take my foot off the gas to begin gliding up to a distant stop light, it feels as if the car is goes into engine breaking and begins to slow down fairly quickly. If I push the gear shift into neutral, the RPMs drop from about 1500 to 1000 and the car glides nicely up to the stop light with a very gentle slow down. In neutral you no longer feel any breaking sensation at all. In drive gear the sensation of breaking is very noticeable.

    I have not had this experience with any other car. For instance my Mercury Sable will glide a long distance with my foot off the gas pedal.

    Is this normal for the Sonata? Won't this contribute to poor gas mileage if the engine is breaking when it's not needed? I have read it's not safe to shift into neutral while coasting?

  • snakeweaselsnakeweasel Member Posts: 19,054
    The engine should give resistance when you take your foot off the gas in any car. You may notice it more in certain cars but I guarantee you that this happened in your Sable too.

    The question I have is do you just accelerate to 30 and take your foot off the gas? or do you cruise for a while at 30? If you accelerate rapidly to 30 then take your foot off the gas then you are most likely in a lower gear and the effect will be greater than if you were cruising in a higher gear.

    2011 Hyundai Sonata, 2014 BMW 428i convertible, 2015 Honda CTX700D

  • mamamia2mamamia2 Member Posts: 707
    This is totaly normal. Some modern cars have it a LOT more pronounced (to a point of annoyance), like the Honda Accord... It's the way modern transmissions are designed today.
  • donx1donx1 Member Posts: 2
    I cruise at 30 mpg for a while and then anticipating some stopping ahead I take my foot off the gas. I checked this morning and the car is in 4th gear. As soon as I take my foot off the gas, I can feel the car engine breaking but it doesn't show any downshifting taking place. If I manually down shift to 3rd the engine breaking becomes significant.

    I did a little test. It takes about 14 seconds for the car to slow from 35mph to 25 mph when it is in gear with my foot off the gas. If I throw the car into neutral immediately after removing my foot from the gas, it takes over 35 seconds to effect the same slow down. A look at the RPMs shows the difference as well, 1500 dropping to about 1000 rmps with my foot off the gas versus an immediate 800 rpms in neutral. I assume that's gas saved but I didn't know if the amount is significant.

    Your right my '95 Sable does show some effect but not nearly as significant as the Sonata. I wondered if it was a breakin thing or if that is permanently how cars behave these days?
  • mamamia2mamamia2 Member Posts: 707
    No, not a break-in issue, and again, this is how most, if not all newer cars behave.

    And again, if you drive an Accord, you'll feel it even more... Actually in the Accord's case, the NEWER Accord has this a bit less pronounced than the older Accord... My '95 Accord was almost annoying the way it would down-shift the second I lift my foot of the pedal, at around 30-40 MPH. Our '05 Accord is more smoothly doing it, but still more noticeable than my Sonata. It's called something like "downgrade logic"...
  • snakeweaselsnakeweasel Member Posts: 19,054
    I did a little test. It takes about 14 seconds for the car to slow from 35mph to 25 mph when it is in gear with my foot off the gas. If I throw the car into neutral immediately after removing my foot from the gas, it takes over 35 seconds to effect the same slow down.

    All cars will have a similar effect. When you put the car into neutral you completely disengage the engine, your RPMs should go to an idle rate. But if you keep it in gear the engine is still engaged and will slow the car down significantly.

    2011 Hyundai Sonata, 2014 BMW 428i convertible, 2015 Honda CTX700D

  • lightfootfllightfootfl Member Posts: 442
    I read on another posting yesterday I think it is possible in some situations and vehicles, that you can "tap" the accelerator pedal after you left off the gas, and it will "disconnect" that drag. I haven't tried it yet on my vehicle, but I am certainly going to give it a try. It can't hurt anything to try. Who knows?
    It may be a definite asset, or it may never work at all. :)
  • ray_h1ray_h1 Member Posts: 1,134
    Even with balance shafts (the Hyundai 2.4L I4 has two of 'em - counter-rotating), larger I4s exhibit more vibration at idle than their smaller cousins. (I'm assuming your Focus didn't have a 2.4L displacement motor.) At only 24K miles, it doesn't seem likely that there're any serious problems present. (But...) You might have a trusted mechanic take a look and advise you whether there's cause for concern. And, if he'll connect his ignition scope up, you'll know whether it's hitting on all four cylinders. (If the motor pulls smoothly under acceleration, it's likely OK, too.)
  • jacknzonejacknzone Member Posts: 82
    My 04 Sonata,has 28000 km there is a sound when at idle and it sound like a diesel ,if you are standing out side by the right front wheel you can hear it ,but in the car you can not hear it at all. It is the injector on my car.
    It take off smooth and when you turn the engine off , the car stop straight away.

    Like ray said ,get some one to have a look at it now. For peace of mind.
  • osaka75osaka75 Member Posts: 88
    I had the same experience with my GLS V6 when new. I also wrote to this board and someone wrote back that it might be the torque converter locking as it should. After slowing down for several seconds, I felt that the "engine braking" freed up and the car would then slow as expected. I have no idea what it was but after a few thousand miles I stopped noticing it. I think it just went away, at least enough that I don't notice it in my everyday driving.

    I'll also add that I think that the transmission is supposed to learn our driving over time. I like how mine performs now better than when new. Perhaps these two items are related.
  • 95sonatav695sonatav6 Member Posts: 1
    95 Sonata, V6 auto. 90K miles. My car starts right up/idles fine on the first start of the day. Car is used for pizza delivery. At a customers house I stop the car, collect the money and restart the car within 2 minutes, it starts fine. But after returning to the pizza store, I might wait 10-15 minutes before I go out on the next run. At this point the car will not hold the idle and dies. I must restart the car 5-6 times as well as revving the engine for about 10 seconds before it will hold(barely). This scenario is the same for each run. What's interesting is that I had this problem in the Fall but it disappeared when winter set in. Now in March, with temps back in the 70s and 80s it's reappeared. Also,if the engine is off for an hour, then it starts fine. Hopefully I've given enough details for someone to make an educated guess. Thanks.
  • lightfootfllightfootfl Member Posts: 442
    TO: Administrator ????
    I have noticed recently that as my mouse goes over the name of the contributor that I get "info" about them. This is fine, except that I haven't figured out how to get rid of that info to read some of the comments under the "tag". I have tried going up and down, etc.. and I can figure out how to read them, but couldn't that "pop-up info" be made to disappear in a few seconds?? I am really more interested in the comments than the info about the contributor. Please consider an adjustment of sorts. Thanks, van
  • patpat Member Posts: 10,421
    It's supposed to disappear if you leave the cursor on the name of the poster for a couple of seconds. As a workaround, try that when it won't go away.

    Meanwhile, the place to talk about this is here: Forums Software.

    You are not alone in your feelings. I'm beginning to like them, but that's because I figured out how to get rid of them when they show up unexpectedly. :)
  • franmartfranmart Member Posts: 16
    how many gts of oil do you use for a oil change
  • bhmr59bhmr59 Member Posts: 1,601
    Apparently you do your own oil changes. If I did, I'd check the owner's manual to see what it says is the required of oil.
  • hotrod54hotrod54 Member Posts: 82
    5.52...but 5.5 is okay
  • cunningham83cunningham83 Member Posts: 1
    this isnt my car but its parked in front of our house and trying to fix it. the problem is when you put the key in the ignition and turn it over, it starts but like a few seconds later, it dies off. the check engine light is on. we checked the battery connection, air filter. im thinking its a bad spark plug but not sure. can anyone help me.
  • hotrod54hotrod54 Member Posts: 82
    There are so many things it could be; you really need to get a diagnostic scan by someone who really knows how to follow the diagnostic tests on the computer scanner.
  • daveridaveri Member Posts: 3
    I bought a 2000 Sonata v4 with around 60,000 miles. recently it has been running rough, stalling and losing power. I took it to the Hyundai dealership and had the 60,000 scheduled maintenance done- plugs, filters, oil change, drive belts etc. I didn't replace the timing belt at that time. The car still runs rough and loses power.Does anyone have an idea as to what could be the problem? Also the price for replacing the timing belt would be $510. This seems a bit high. Is it necessary to go through a factor dealership for this maintenance or can I go to a less expensive garage?
  • hotrod54hotrod54 Member Posts: 82
    You can go to any qualified mechanic for a timing belt. As for running rough, (by the way, it is an I4), did you have the fuel filter checked; it could also be carbon buildup on intake and exhaust valves or low flow/clogged fuel injectors...find a BG products supplier and and get a can of BG44k, put it in tank and see if that helps. ;)
  • tinquitinqui Member Posts: 2
    2003 hyundia sonata running great and with out early indications the eng misfires and eng light came on. has 34160 miles.
  • targettuningtargettuning Member Posts: 1,371
    Your best bet is have a dealer actually read the code/s stored to find out what the possible malfunction might be. Some auto parts stores (Advance for one) will read the codes,if any, for free. Since there are various sensors seeded throughout the engine/transmission it could be a subtle fault you may not even feel or hear.
  • craigbrookscraigbrooks Member Posts: 420
    Checker Auto Parts will read the codes too. They will even give you a print out to take to your mechanic so you save the "hook-up the old analyzer" fee.
  • kimweigelkimweigel Member Posts: 43
    Let me start by saying I am very impressed with the new model Sonata (NF). So much that after buying a new '07 for the wife, I looked for myself and found a nice used '06 for myself. Both of them have the V6 / leather / climate control. Anyway, my '06 had an engine rattle on startup, just about 5 seconds, like a can full of ball bearings. I took it down to my local Hyundai dealer, and they took out the engine, replaced 2 timing chain tensioners (TSB number 06-20-002) changed the oil, and replaced the rear shocks (another TSB). Total cost to me: $0.00.
    Now the rattle is gone, so is the rear end clunking (like an old car with bad ball joints) The car is just smooth, quiet, and tight, just like my wife's brandee new '07.
    I'm really impressed with the dealership, that they got everything back together right with no leaks, squeaks, rattles, or other problems. Kudos to Hyundai and it's service department and the people who train and select their employees.
  • tinquitinqui Member Posts: 2
    The eng ran fine for a few minutes, eng light still on but when it eng warmed up the eng started to misfired again.
  • targettuningtargettuning Member Posts: 1,371
    Take my/our advice and have the codes read, then instead of the guesses I and others here tender you will probably have an answer and be able to have it fixed. My guess is ignition...plugs, wires, etc
  • create38create38 Member Posts: 3
    my sonata runs fine but recently the engine light came on right after i installed a new battery, pls advise
  • create38create38 Member Posts: 3
    can someone please tell me where do you hookup the analyzer to read codes on the 01 sonata

  • targettuningtargettuning Member Posts: 1,371
    I assume you are asking about a handheld OBDII code reader? If so, there is a port under the left side of the dash (this is where they are on later model Hyundai products). It has a plastic cover on it that may be labled as an access port for OBDII diagnostics.
  • blackopalblackopal Member Posts: 1
    You mention that your 06 Sonata has a timing chain and the replacement of the tensioners solves the rettling ptoblem.

    I have a Check Engine Light problem with my 06 ^ and suggested to the service dept that it might be a 'chain' problem and they said it wasn't possible.

    Would tensioners solve the CEL problem in your opinion?

    The car has 14M miles and has had 2 ignition coils replaced along with an O2 sensor , 6 new plugs and wires. Currently it is in the shop for the third time in as many months.

    Any suggestion on what the dealers mechanic might look for?

    Thanx in advance for any help you can give.
  • lcm123lcm123 Member Posts: 1
    Hello All, I have a 2007 I4 GLS with XM and I get a vibration from the car between 40-45mph and I was wondering if any one else has the same problem? It doesn't happen at any other speed
  • drezworlddrezworld Member Posts: 1
    I have a 2000 Hyundai Sonata w/ 130k. Well the motor over heated and blow the radiator.When adding coolant to the new radiator the coolant is pouring out of the oil filter. Why is that??
  • autokritikerautokritiker Member Posts: 65
    A guy at work has a last generation 2002 Sonata 4cyl manual, with a few mechanical modifications. Nothing major or internal: just intake, chip, exaust, etc. He was able to defeat the rev limiter, and he claims he can rev the engine to just over 8,000 RPM before shifting.

    I haven't driven or ridden in his car, so I haven't actually witnessed the tachometer climbing that high. Here's my question:

    Does anyone in here have a Sonata with a defeated rev limiter (don´t worry, I won´t ask you for your VIN :D ).

    If so, have you been able to rev your engine that high? How often? The redline on the I4 and V6 Sonata engines is somewhere between 6,200 and 6,700 RPM depending on the year/engine.

    I'd be interested to see if anyone else is able to rev their Sonata engine past 8K
    without blowing it up.
  • ctc1ctc1 Member Posts: 66
    Blown head gasket.
  • hotrod54hotrod54 Member Posts: 82
    Okay, let's figure this out. Since there is an incredible lack of info, this post will be full of questions. You say the engine overheated and the radiator "blew out" and coolant now comes out the oil filter. Do you know why the car overheated? I am presuming that if coolant comes out the oil filter, well by golly, so has the oil. So, did the engine overheat because there was no oil in the engine? If so, your engine is toast. You say the radiator blew...just what does that mean? Did you or a shop replace the radiator? Are you just jerking our respective chains? :mad: :confuse: :mad:
  • craigbrookscraigbrooks Member Posts: 420
    why? Max torque and HP are achieved way B4 these RPM's. What's the point?
  • hotrod54hotrod54 Member Posts: 82
    Exactly. ;)
  • autokritikerautokritiker Member Posts: 65
    If an engine is able to breathe better, wouldn't the HP peak occure at higher RPM? I thought the power peak usually happens after an engine "runs out of breath" as they say.

    With better breathing, and a tweaked chip to push more fuel into the engine at high RPM, and maybe some bigger injectors, you'd assume an engine would make more power at a higher -RPM power peak.

    The question is, how long could the engine's internals handle the extra RPM and power? I guess we don't have any Hyundai "ricers" in here yet.
  • autokritikerautokritiker Member Posts: 65
    ...I meant, the power peak occurs just before the engine "runs out of breath"
  • n5wxbn5wxb Member Posts: 1
    Went to go to store car would not start. 5 Minutes of trying got it 2 start once for 3 seconds. Killed battery and waited for jump. tried for another 5-10 Minutes it started for 10-15 seconds. I can hear the Fuel pump starting when i turn on Ignition, but can't smell gas, I'm thinking Fuel filter. if I am correct where is the filter. any other possibilities????
  • jlindhjlindh Member Posts: 282
    I have a problem imagining a fuel filter that would just clog all of a sudden without previous signs of starvation under high power.
  • shadow26shadow26 Member Posts: 4
    Update to "thunking" on 2008 Sonata. I have been in contact with Hyundai Consumer Reps. They have assigned a case number. They were pleasent yet unable to help. Both reps. I spoke with had NOT heard of this problem. They contacted the dealer, also set up an appointment with a Hyndai rep. After a test drive with the rep and Service manager at the dealership, the results were this. The thunking is normal for this type of suspension, it is a tuned "sport" suspension allowing for sports car performance rather than a soft ride, it is a "stiffer" suspension than other Hyundais.This car is a four cylinder, when I asked the rep why I have read reports that the six cylider does not seem to have this condition he stated because it is a heavier vehicle. The rep was willing to change out the struts, however he belived this would NOT change the condition. The dealership was willing to trade the vehicle with a trade in price of $15,000 - the taotal price I paid was $23,200. less than a month ago !!! No suprise there!!! I am going to take the car to a mechanic I trust and have him evaluate the situation. I' ll proceed from there. I do believe that Edmunds and all other organizations which post car reviews should include this condition in there reports.
  • targettuningtargettuning Member Posts: 1,371
    That 2006 -07 and I guess 08 Sonata's have noisy suspensions is old news in as much as there have been posts here and Hyundai has issued a TSB to correct or minimize REAR suspension "thunks" on 2006 cars. There now seems to be FRONT suspension noise classified by some owners to be a "thunk". I have been following a specific owners process using a Hyundai repair facility to remove his front noise and the latest on that front, as reported recently, is that the front strut cartridges or inserts have been changed. This minimized but did not eliminate it.
    I do not agree with your service advisor about either comment he made: that a "sport suspension" is inherently noisier than the "normal" version on the same car or that a V-6 being heavier (it may be but it is minimal) would cause one not to have the noise. I personally have recently rented both I-4 and V-6 versions of the GLS model. These were 2007's and having ~26,000 rental miles were hard used vehicles. I don't know if I am insensitive or what but driving both cars over temporary "winter patched" repairs on generally poor Pa roads I MAY have heard some suspension noise on the worst parts. Would this noise have been apparent if I was driving a Camry, Accord or some other brand car? I suspect so but don't know for sure. I have come to the tentative conclusion that individual owner sensitivity to noises may play a part in this "problem".
  • craigbrookscraigbrooks Member Posts: 420
    I would have the dealer replace the front struts and go from there. It may solve your problem. If they want to do something for free let them.
This discussion has been closed.