Unusual sound from engine at around 50-80km/h on Golf VI 103TDI

[khamtran]

For the last couple of weeks my Golf VI 103TDI has been making a low frequency but continuous whoop whoop whoop sound which appears to be coming from the engine when cursing at speeds between 50-80km/h. Above 100km/h the sound cannot be heard.

The sound has recently got louder after and during a road trip to Sydney from Melbourne. The sound isn't really loud but I can certainly hear it. My girlfriend says she only noticed if after I mentioned it so it isn't totally noticeable.

I'm just worried it could be the beginning of a problem. The car is driving perfectly well though.

Does anyone have any ideas?

[mikinoz]

Just check you don't have something stuck in your tyres bro. I had some strange effects from bits of blue metal in the grooves.

[TDI DSG]

Is it at around 1200 - 1400 rpm and once the rpm gets higher it goes away ?

[khamtran]

Just check you don't have something stuck in your tyres bro. I had some strange effects from bits of blue metal in the grooves.

Thanks mikinoz. I will give the tyres a good check over.

[khamtran]

Is it at around 1200 - 1400 rpm and once the rpm gets higher it goes away ?

That certainly appears to be the case. While cruising at 1900rpm I couldn't hear it at all.

[TDI DSG]

I have a new wagon with this same vibe.
How many klms have you done ?

[khamtran]

Mine has just over 20,000km on the clock.

[TDI DSG]

Mine has just over 20,000km on the clock.

Have you not noticed anything similar previously ?

[benough]

Well the turbo's in those spool up at 1300rpm.

That's not conclusive but it could be related?

[khamtran]

Have you not noticed anything similar previously ?

I only noticed it about 2 weeks ago but it became more apparent after the drive from Melbourne to Sydney this Easter long weekend.

I'm just hoping it's just something stuck in a tyre tread. I'll have to wait until the weekend before I can give the tyres a thorough examination though.

[khamtran]

Well the turbo's in those spool up at 1300rpm.

That's not conclusive but it could be related?

I'm not sure but I hope not. Performance hasn't been affected at all.

[khamtran]

I have thoroughly checked all tyres and haven't found anything apart from some very small stones which I removed.

Sadly, the sound is still there.

Is it possible that the sound could be caused by a wheel balance issue? I originally didn't think this was likely as there is no vibration at the wheel or in the car at high speed. The car also drives dead straight without me holding the wheel.

Do I have any other options than to bring it into the dealer?

[Greg Roles]

Seems odd it is only at a particular speed, and not specific revs in each gear. Makes me think the engine tray is loose and flapping around, sounds more like an aerodynamic effect than an engine thing based on speed alone.....but all you can do is drive around with the windows down and try to pinpoint it, but yeah, the dealer may be the best option, may need some serious problem solving.

[khamtran]

After some more driving and careful listening I can hear the sound (and slightly feel it) at speeds below 60km/h. As the speed drops the frequency of the sound slows too. A member from the TDIClub.com forums suggested that it could be a wheel bearing problem.

It is also possible that it could be a aerodynamic effect. I had a good look and feel around the endtry tray and it feels secure.

I think I may have to take the car into the dealer and have it checked out.

[khamtran]

I took the car into VW today and went with the technician for a drive.

He said the noise was definitely coming from tyres and that it appears that "tyre scalloping" is the issue. He also said that it sounds like it's coming from all tyres.

VW recommended that I take the car into Beaurepaires to have it properly checked which I am planning on doing.

The noise is best described as a drumming sound. Has anyone else experienced this issue?

My car has done just over 22,000km and the tyres were first and last rotated at 13,000km. The tyres are the OEM 17" Bridgestone Potenzas on stock suspension.