My Superb III was serviced last week, including Air Con service and DSG Oil Change. Mileage is 35k. Since the service I've driven 200 miles and this weird hooting/whine noise that I have never heard before has happened on three occasions.  My theory is it may be gearbox related as it is occurring when slowing down/accelerating, and it's too much of a coincidence that it's right after DSG work.

 

Fortuitously I've captured the noise on my Dashcam (which I thought had audio recording turned off but actually it didn't). Can anyone have a listen to the links below and weigh in with any thoughts on what the noise is and should I be concerned about it?

 

https://youtu.be/PvBkttTAZFs?t=7
 

https://youtu.be/sTtVLMPcMGY?t=5

 

https://youtu.be/oCbrP7szNJQ?t=5

 

Edit: even if it's not something I should be concerned about can anyone tell me what needs to be done to get it to stop, as it's irritating and the car didn't used to do it!

Edited 25 April, 20224 yr by Tom_G

Sounds possessed to me.

 

I’d find somewhere near where you had the work done and see if you can replicate it near, then get a mechanic in the car with you, just make sure you can hear the noise on the same part of the road.

 

Might be worth getting someone you know to see if it makes that sound outside

Solenoid / diverter valve; ruptured diaphragm; boost leak ? Or some associated hose / part? PCV valve? The noise sounds like the boy racers who modify their turbo setup with blowoff valves to make a similar noise. Apparently this is desirable in certain quarters.

An update - so far the car has been back to the garage twice. They can't reliably replicate the issue and neither can I, although it sometimes happens often there is no consistency which is the issue. I've driven almost two weeks with no noise, and then had another week where it was happening frequently.

 

My best working theory so far after another month and a half of driving is that the air filter installed during the service is either slightly misfitting or faulty in some way, and is acting like a 'reed' as air is sucked through it into the turbo. The large tubing on the way to the turbo might be amplifying the noise originating in the filter.

 

Is this theory at least vaguely plausible or is it completely unlikely? I've got a bunch of other recordings, I'll try and find some of the best examples and post them this weekend.