Strange sound above ~80km/h

[krisman1993]

Hi everyone, new member here. I bought a 2019 Skoda Octavia Mk3 1.5 TSI DSG with 80.000 km, I believe it's the dry-clutch one. I noticed that the car has a strange sound above 75-80km/h. I took the car to a mechanic, who plugged it on a computer and said that the car is in perfect condition mechanically, despite that sound. So now, I'm turning to you, in the hope that someone can recognize the problem. I'm uploading a video here, on which you can faintly hear the sound. It's kind of hard to hear.

Thank you in advance.

[fr1nklyn]

Hi @krisman1993, it’s hard to hear the sound on this video. Maybe if you can record the transition from not having the noise to when it starts to be heard, that would help.

 

Did the noise started after tires swap or any repair? Or maybe after some light offroad trip?

Has the noise increased over time?

 

A common fault on the MQB platform are the wheel bearings, but could be anything else, from engine undercover if it’s been hit and loose, to tires, even the DSG transmission which is unlikely on this mileage and so on.

 

If it’s a worn wheel bearing the noise from it usually stops or gets louder on left or right turn, depending on which side the issue is.

[krisman1993]

Thank you for your reply! Sadly, that's the best I can do right now, since the sound is pretty low. Also, there's no real transition from not having the sound, to when it starts, because the sound only happens for like 0,5 seconds every 2 to 10 seconds. It's not regular.

I've had the car for 2 months and I've heard the noise since. Sadly, I don't know if the prevous owner had this problem. There was no recent tire swap or repair, and no offroad trip either. As far as I know, the car was never hit.

What I noticed yesterday though, when I took over a car in front of me, the sound increased in volume with the sudden turning and pressure to the left front wheel, for the duration of the turn. This time I definitely heard the sound from that wheel. When I straightened the wheel, it got back quieter.

The tires are also year 2019 and I don't have tires for winter yet.

[GreenMachine1.6]

I cannot make out the noise from the recording. You said the noise was noticeable when turning and loading the wheel. Bit of a long shot, could it be a stone trapped between the brake disc and shield? I've had a number of these and are the devil's own trying to track them down. 

[fr1nklyn]

If the noise isn't regular, it's not a wheel bearing.

[J.R.]

3 hours ago, krisman1993 said:

I took the car to a mechanic, who plugged it on a computer and said that the car is in perfect condition mechanically

 

The comment says it all really 😒I have nothing to add other than keep clear of mechanics like that.

[krisman1993]

Yeah, it's safe to say that I'm not going back to that mechanic 😀 The noise is not regular, sometimes I go 20 minutes without hearing the noise once, and then it suddenly starts.

Is it possible that the fault is in the dual mass flywheel? Or does it just need a suspension calibrating? Just asking because these things were often mentioned, as I was trying to research my problem.

Thank you all for your input. Please bear with me and my possibly stupid questions, as my knowledge about cars is pretty d*mn small.

[PetrolDave]

3 minutes ago, krisman1993 said:

Please bear with me and my possibly stupid questions

The best answer is to take the car to a mechanic who understands mechanics and is not just a 'keyboard jockey' with a diagnostics tool.

 

Diagnostics only cover parts of the car managed by electronics, and that excludes nearly all of the mechanical parts.

[Gabbo]

Does the sound get worse as you go faster? 

E.g. At 60/80/100kph/120kph/160kph? 

[MarkyG82]

Can you describe the sound? Is it low pitch or higher. What area of the car is it coming from. Can you feel anything at the time. Are the windows open. 

 

If it's a low pitch thrumming noise with the windows open as you pass through 80+ then it's a "feature". Try it with the windows closed. It's an aerodynamic issue.

 

Otherwise we still need more info to help pin down a possible problem. Definitely doesn't sound like a wheel bearing.

[krisman1993]

16 hours ago, Gabbo said:

Does the sound get worse as you go faster? 

E.g. At 60/80/100kph/120kph/160kph? 

No, the sound remains the same at all speeds, but only happens above 75-80 km/h. It doesn't matter if it's 80, or 160, the volume, the intensity, the pitch is the same. As far as I can tell, it's not dependant on the wind.

 

 

1 hour ago, MarkyG82 said:

Can you describe the sound? Is it low pitch or higher. What area of the car is it coming from. Can you feel anything at the time. Are the windows open. 

 

If it's a low pitch thrumming noise with the windows open as you pass through 80+ then it's a "feature". Try it with the windows closed. It's an aerodynamic issue.

 

Otherwise we still need more info to help pin down a possible problem. Definitely doesn't sound like a wheel bearing.

The sound is definitely coming from the front, but from which part or side, I can't really say. Mainly I hear it from the middle, but I noticed while taking over a car in front of me, loading the front left wheel increased the sound. It's kind of hard to describe the sound because of my english vocabulary, but it's like a vibrating sound and more low-pitch, than high that lasts for about 0,5-1 seconds, every couple of seconds. But there are times, when the car does not make that sound for longer periods. The windows were closed.

Today I will check under the undercovers if there's anything loose, but that won't be the issue probably. I'm in the process of finding another mechanic as well.

[PetrolDave]

2 minutes ago, krisman1993 said:

No, the sound remains the same at all speeds, but only happens above 75-80 km/h.

 

it's like a vibrating sound and more low-pitch, than high that lasts for about 0,5-1 seconds, every couple of seconds.

Today I will check under the undercovers if there's anything loose, but that won't be the issue probably

I wouldn't agree that loose covers/trim isn't the problem, because what you describe sounds like a loose piece of trim or cover to me - that's fairly tight so it only vibrates when the vehicle speed is high enough for the airflow to make it vibrate.

[krisman1993]

14 minutes ago, PetrolDave said:

I wouldn't agree that loose covers/trim isn't the problem, because what you describe sounds like a loose piece of trim or cover to me - that's fairly tight so it only vibrates when the vehicle speed is high enough for the airflow to make it vibrate.

You are right, what I meant to say is, that they were checked (two months ago, when I bought the car). Sorry, for being misleading.

I will be more thorough today, after work.