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Hi all. I’ve just changed the timing belt on my 1.4 TDI (CUSA engine). After starting the car I’ve noticed a whine that I believe is coming from the belt, and increases pitch with RPM. I didn’t notice this noise before changing the belt and I’m now pulling my hair out trying to find the cause.

I followed the workshop manual which I got online and found changing the belt easy enough. I’ve double checked everything and have even taken the belt off again and put it on, making sure everything was done correctly but the noise is still there.

The tensioner is set correctly.
Tensioner, idler and water pump have all been replaced.
Belt is not rubbing on any covers.
Timing is set correctly as per the manual.
Have started the car with the auxiliary belt left off and the noise is still there.

Anyone have any idea what I’ve missed or is this noise normal for a new belt (i.e. does it just have to brake in and the noise will go away)? Most people online would say the tensioner is set too tight but I’ve checked and re checked and it’s right on the money.

The belt is a gates power grip kit (KP25678XS) which is the same as what was on the car before.

Here’s a video of the noise.

https://youtube.com/shorts/UueG1RxOVzk? ... OPMaBmXvN5

If it was mine I would drive it and monitor the noise if your 100% sure everything is set correctly, it may as you say ‘bed in’ although it shouldn’t have to.

At this point I’m certain everything is installed and set correctly. I tried loosening the tensioner and starting the car and after doing this the noise was gone. This left the tensioner set far too loose though and I’d be scared it would skip a tooth if I left it like this. I’ve also bought and installed another new tensioner thinking the one I had wasn’t set right from factory but the whine is still there.

I think as you say I will drive it and pay close attention to the noise. Hopefully it fades away after a few heat cycles.