3.8 AWD knocking sound issue (video)

[ssyong0520]

I could hear the engine knocking sound between 24-30mph speed rage. Hyundai dealership found that the problem came from dashboard and they adjusted the plastic dashboard. After that, It was not fixed and I went to Hyundai again and they found that the sound came from cowl cover. So they adjusted the cowl cover. However, It was not fixed after that attempt. So i went to Hyundai again and they are now investigating the problems. I don't think its plastic or that kind of problem.

Do you guys have any idea what this sound is?
I can hear when engine is cool if i drive more than 5 miles, getting smaller sound.
Help me

Here is Video (updated)
https://youtu.be/9RxjYgQ_4Hg

 

[Nikgen]

I could hear the engine knocking sound between 24-30mph speed rage. Hyundai dealership found that the problem came from dashboard and they adjusted the plastic dashboard. After that, It was not fixed and I went to Hyundai again and they found that the sound came from cowl cover. So they adjusted the cowl cover. However, It was not fixed after that attempt. So i went to Hyundai again and they are now investigating the problems. I don't think its plastic or that kind of problem.

Do you guys have any idea what this sound is?
I can hear when engine is cool if i drive more than 5 miles, getting smaller sound.
Help me

Here is Video
https://youtu.be/r59x5Osterk

I have not experienced that - Is the sound coming from the dash area you focused the camera on? It's not an engine knocking sound - I'd call it a harsh vibration sound. Does it go away at higher speeds? It almost sounds like something vibrating/oscillating as it flaps in the wind?

 

[xsolara]

The sound to me sounds like a plastic gear that not making good contact with another gear...very difficult to hear using that video's audio
This is sure a mystery
Try something..readjust the steering column to a different position - up down in out and see if sound changes

 

[ssyong0520]

The sound only happen when speed range between 24-30 and engine cool down. if I speed up, no sound even slow down.

 

[ssyong0520]

I have not experienced that - Is the sound coming from the dash area you focused the camera on? It's not an engine knocking sound - I'd call it a harsh vibration sound. Does it go away at higher speeds? It almost sounds like something vibrating/oscillating as it flaps in the wind?

It goes away at higher speed even lower speed. it sounds like really engine knocking sound but not sure.

 

[homeofstone]

Sounds like the GDI engine or an exhaust gasket leak. GDI engines do have injector sounds like in the video.

 

[ssyong0520]

Sounds like the GDI engine or an exhaust gasket leak. GDI engines do have injector sounds like in the video.

They don't even try to investigate the engine. Keep saying other things. i don't know why they are doing like that.

 

[homeofstone]

A mechanic's stethoscope is a great way to narrow down where a noise is coming from.

 

[srobak]

Here is Video
https://youtu.be/r59x5Osterk

Sounds to me like plastic cowling flapping around in the breeze... possibly under the car. The fact that it is speed dependent and not RPM dependent all but eliminates the engine.

A mechanic's stethoscope is a great way to narrow down where a noise is coming from.

Yep. At least one mechanic in the shop will have one of these. If not - find a new Hyundai dealer.

 

[ssyong0520]

Sounds to me like plastic cowling flapping around in the breeze... possibly under the car. The fact that it is speed dependent and not RPM dependent all but eliminates the engine.



Yep. At least one mechanic in the shop will have one of these. If not - find a new Hyundai dealer.

They should have it. If the problem is plastic or kind of that things, It should happen any speed range not especially 24-30...i guess.. and If I ride more than 5 miles, this thing simply disappear. I visited dealership for 3 times and seems like they really don't have idea of this problem.

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[srobak]

If I were you - I'd put the car up on jack stands, make sure it is cold and then go underneath and start banging around plastic pieces to see if any are loose & knocking at one of the bolt/screw holes. Pay attention to the ones nearest the exhaust. When cold they may move just enough to go flapping around at the speed you indicate - and once warmed up they swell just enough to stop. Also just for giggles - do the same near any heat shields you find. Additionally - pop the hood and knock around on the cold plastic under there too...

 

[Alwaysforward]

Not sure if you have a Go-Pro camera or other type of sound recording device but you could mount it under the hood and see if that sound is more pronounced there. If it was the engine, it should be noticibly louder. You could duct tape your cell phone under the hood. My guess is same as noted above. Sounds like plastic but ruling out the motor would be my first step.

 

[svensk]

It's not from the engine. I've heard that sound before in other vehicles. It's something with a fan in the dash. The bearing is either shot in the fan or it's hitting an obstruction making that clicking sound.

 

[ssyong0520]

If I were you - I'd put the car up on jack stands, make sure it is cold and then go underneath and start banging around plastic pieces to see if any are loose & knocking at one of the bolt/screw holes. Pay attention to the ones nearest the exhaust. When cold they may move just enough to go flapping around at the speed you indicate - and once warmed up they swell just enough to stop. Also just for giggles - do the same near any heat shields you find. Additionally - pop the hood and knock around on the cold plastic under there too...

That's almost difficult to do it by my self.. I'm just ordinary person and don't have skills of it.. I will inform that to my dealer! Thank you for your advise.

 

[ssyong0520]

It's not from the engine. I've heard that sound before in other vehicles. It's something with a fan in the dash. The bearing is either shot in the fan or it's hitting an obstruction making that clicking sound.

Thank you for your advise. You mean under the hood? or dashboard? does it have relationship between certain speed rage like me?

 

[lobsenza]

Turn off the ventilation system and see if the sound changes.