My car is a 2016 Octavia 1.4 tsi DSG. 

 

Each time I cold start it then drive off, the car starts producing a whining sound that increases in volume as I speed up and go through the gears. The sound peaks and then starts dropping off again as I get to speed. I can hear it over the radio but it doesn't drown it out. The noise is also very noticeable from the outside of the car, my parents have informed me. Seems to be coming from under the bonnet.

 

For the sound to happen, I have to be using the gas pedal. It does it either reversing or going forwards. The whine seems to decrease in pitch then stops when I lift off the gas. I've tried running the car for longer before I drive off and it's made no difference. The noise gets quieter over the course of about 30 seconds then stops. 

 

In the attached audio file, I drive off

 from my work car park after a cold start. I accelerate up to about 30mph then pull over again. The noise continued for about a minute after this (only when accelerating), but progressively got much quieter. I've tried all combinations of fans on/off, AC on/off in case that might be the cause and I don't think this is making any difference. In this recording I had the fan running on its lowest setting but switched the AC off.

 

I'm sure it's started doing this since I had it mapped in August, or at least around that time. It seems to be getting worse now and lasting for longer.

 

May be entirely unrelated, but my car has always made an extremely similar sound between 25-27mph, only when coasting. For example, lift off the gas at 30mph and it starts to whine at 27 mph then stops as it slows down past 25mph. Weirdly specific I know.

 

Thoughts?

Simple stuff first, check all the hoses are in situ under the bonnet, especially hoses related to air intake / vacuum. They should all be in good nick and no cracks (check them all!).

 

Someone else will be here hopefully who can just look into the crystal ball and know, but i'd start there.

I'm yet to check under my bonnet though the sound has been very intermittent. I've been trying to keep an eye on what conditions it does it under. It seems that it is only doing it on a cold start, when the temperature is above 15C and when it is dry. If it's a bit damp but the temperature is higher, it does it a little bit. When I leave for work and it's about 11C outside and condensation everywhere, it doesn't make any noise. This all explains why I heard it much more over the summer and now only in the afternoons. Here's another audio from today. This was a cold start this afternoon in very dry conditions and about 16-17 degrees.

 

The noise seems to get louder and higher in pitch either as I go up the revs or if I mash the throttle harder. Hard to tell.

Edited 4 October, 20232 yr by OctyMax98

I hope you can help..... Did you find the root cause if this sound.... Which is exactly the sound my superb makes ( same engine!!!!)

Kind regards

Simon

2 minutes ago, simonletchford said:

I hope you can help..... Did you find the root cause if this sound.... Which is exactly the sound my superb makes ( same engine!!!!)

Kind regards

Simon

I hope you get an answer, Simon.

All too often people document a problem and fail to document the solution. 🙄