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2017 Hyundai Tucson AWD "knock" noise on acceleration

2017 Hyundai Tucson AWD 2.0
5400 KM

Hey guys,
I have a brand new Tucson AWD, purchased the vehicle in March 2017. It has been about 2-3 months I have realized there is a noise each time I accelerate with the car. The noise happens once only and is not continuous. I have tried to piece as much info I can about the issue and I have this:

  • the noise sounds like a light “knock” coming from the right side of the car, not quite sure if it is front or rear (dealership service has looked into rear and have not found a problem, will explain later).
  • when I turn on the car and put the car in drive and begin to accelerate, the noise always happens at 29-30 KM (ALWAYS that KM).
  • it happens regardless of direction, going straight or turning.
  • as mentioned this sound happens once and never again until I shut off the engine and re-start the car to drive off again (regardless of time interval of car being shut ex. I have gone to the corner store heard the noise, parked the car once getting there, stayed in the store 5 minutes, got back in the car took off and the noise happened again like always).
  • if I apply my brakes before 29-30 km, the noise will still happen after I get back up to 29-30 km.

I have been in and out of the Hyundai dealership garage I bought the car (because of the warranty). So far they have checked the rear right end of the car and not solved the problem, they have changed:

  • the muffler, close valve & viscous coupling in the diff.

Need any help I can get to take back to the dealer as they are out of ideas, this is getting very frustrating so I apologize for the story book but if I can get any help at all you guys are the best!


To check, if you accelerate from a start, you hear the noise when you accelerate past 30 km/hr. If you slow down to say 20 km/hr and accelerate again, you do NOT hear the noise when you pass 30 km/hr the second time.

If requires the engine be shut off to happen. What if you stop, put the transmission into park, then drive, does it reoccur?

This is an automatic transmission. Does this happen regardless of what gear? If you accelerate more briskly, which would keep it in a lower gear, does the same thing occur?

When I accelerate and reach 30km I hear the noise. Once the noise happens past 30 km, I can slow down to 0 km a complete stop and accelerate again and I will NOT hear the noise for a second time. It is really just the one initial time.

If the engine is running and the noise happens and I then stop and put it in park while the engine is still running and then put it into drive and drive off, it will NOT reoccur. If I would park and shut off the engine and then turn the engine back on, then the noise would happen again.

Yes it happens regardless of the gear, whether I take off quickly or take off slowly, the noise always happens at 30km.

My first thought is the ABS self test, which is normal and happens once per startup typically, after reaching a certain speed. My jeep has a definite clunk when it happens. That said, 30 km/h seems a bit fast for that test to happen.


These complaints are for the 2016 Tucson.

I believe that the OP is hearing the normal ABS self test. 30 kmh =equals 18 mph, and while that is a little faster than the speed at which my cars have gone through the ABS self-test, it isn’t a whole lot faster.

The dealership probably wouldn’t agree to do this, but if the ABS fuse was pulled, and if the noise was not heard, that would seem to prove that the OP is merely hearing the normal ABS self-test. It should be noted that some models produce a louder noise than others when the self-test takes place, some seem to produce no noise, and the effect can even vary a bit from one vehicle to another of the same make and model.

1 Like

I owned a 2006 Accord V6 that did this exact same thing. It would only do it when the drivetrain was “cold.” The dealer was great, good people and good intentions, but they could not find the issue. I got frustrated and laid down on the ground and kick-shoved the muffler and it made the sound. They replaced it. And then the second one and the problem went away and never came back. I realize an Accord is not a Tucson. Good luck!

From my multiple visits to the dealership, they have confirmed that the noise is not supposed to be happening on the car.
So if the ABS self-test is a normality on a car, I would have to think that the issue would not arise from the ABS test.
As mentioned above, they have changed the muffler, close valve and the viscous coupling in the differential and nothing has worked.

First make sure it isn’t something inside the car or trunk that’s moving, like the jack or spare tire. Remove all that stuff and take a test drive. Next, ask your shop to check the lock up torque converter function. It may be engaging a little too early. Ask to take a test drive in another new car. same make/model/yr & configured as much like this one that they have on the lot, see if you notice the same sound.

The shop already tested another car exactly same as mine to see if they can replicate the sound and there was no sound on the other car, which is why they know something is not right. Thanks for the suggestion of the torque converter I will mention it to the shop.

Hi everyone. I recently purchased a 2017 Hyundai Tucson AWD and I have the same knocking sound that Phil described here. It happens once every time the car starts and starts rolling and will not happen again until I stop and turn off the car. Given that Phil is not the only one with this “issue”, I am leaning towards the thought that it may be normal.

On a different note, other than the knock at startups, my radio unit, if the AV is turned off over night (by pushing the off button before turning the vehicle off), once I start the vehicle the next morning, there is no sound whatsoever once I push the AV on button until I press the XM radio or any other media button, at which time the sound comes on. I googled this issue and found that some people are having it. One guy had the amp, radio unit and speakers replaced without success so I am beginning to think that this is more like a software issue rather than a hardware issue. Anyone can provide input on this?

Thank you in advance.

Sounds that occur soon after start up can be the abs system doing a self test. If so, that would be normal.

I have a 2l 2 wheel drive with exactly the same noise evertime i accelerate
only one time and only if i shut off the engine even for 1 minute

this seems to be a self test of the abs or maybe i was thinking sme kind
of valve in the feul tank that closes and reopens to let the fuel flow.
yes it is annoying and not knowing is where it is from is why Hyundai
should dig deeper or just let us know if it is normal for this `thud`` to occur
They will be hearing from me stay tuned i will be contacting them Monday the 25
good day

Good morning!

I took the car to the dealer and two different mechanics (without speaking with each other) confirmed what everyone has been saying up here:
ABS self-test and/or in some cars it may be the transmission that emanates a louder thud sound when shifting at startup.
Long story short, this is perfectly normal and nothing to worry about. Thank you for all the comments.

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Thanks for the update Satellite.Why would they mention the transmission,that seems
a little odd…ABS self test makes more sense.Actually mine seems to do the test at 15 and 30 km /hr.
Did they mention this,just curious now at this stage of the discussion. thanks

Hi Mike.
I was thinking the same thing when they mentioned the transmission, that it was odd, and I quite frankly I think it has nothing to do with the transmission.
Mine does it at 15km/h also but that thud is less audible and I can clearly hear the thud at 30 km/h.

Hi Phil,
If you want contact me at
I am from laval quebec and i believe i saw another post
that you are from Laval too! What a coincidence! My Tucson
does the same knock noise…what dealer do you go to ?

Mike, I would suggest clicking on @fperillo.92 avatar and sending him a message with your email address directly instead of posting it publicly online. (click on the pencil to edit it out of your post)

Thanks guys! My wife has a 2018 Tucson AWD turbo with only 1500 mi with the same noise as all of you have described. Regardless of how long it sits, the same popping noise. I’m now hearing it at least twice when you slowly accelerate. I have an appt to take it into the dealership and prefer to be prepared with some options to share with the technician. In the meantime, not a bad idea to remove ( if possible ) the ABS fuse and see if that works. Any updates to share with me before I take it in would be greatly appreciated.