Hi guys,

 

I changed the timing belt, water pump and all the pulleys approx 5000 km ago (3 months) on my Octavia SDi. Possibly I have not noticed before, but there is a noise from the engine, when the engine is warmed up. It is a whining sound (almost comparable to turbo noise, but not that significant) that changes with the rpm.

 

I thought that it is the flywheel, but the sound is the same whether the clutch is pressed or not. And the noise definitely comes from the area near the timing belt/assembly.

 

I have checked the tension. It seems to me that it is really tensioned (way more than the old timing belt was), but the tension pulley is set right.

 

´The thing that riddles me is why the sound is only generated when the engine is warmed up.

 

Do You have any experience with that?

 

Thanks for Your answers in advance.

Edited 30 June, 201510 yr by Filipo

In my experience, this kind of whining noise is USUALLY either the alternator, or the power steering pump.

 

An easy way to locate a noise is to get hold of a large, long screwdriver, or something similar - basically a long metal tool with a plastic handle on the end.

 

Then, go into the engine bay, and press the metal end of the tool against different parts and places where you suspect the noise might be coming from - and then push your ear onto the other plastic end of the tool.

 

The tool will work well as a kind of 'stethoscope' - you'll hear the different noises in your ear quite well. By moving the tool and pressing it onto lots of different places, you will then quickly find the source of the whine.

 

Try it - it works!

Also inspect the auxiliary drive belt really carefully, full run and both sides. I had something similar which ended in a broken belt and VOR for a week whilst I sourced a replacement.

Or there is a possibility that I am looking for a failure that is not there. I took a video of me reving the engine. I admit the first couple seconds are useless but after I opened the door You can hear the engine noise more clear. I guess there is nothing there ...

 

https://www.youtube.com/watch?v=F-rgoa7qpXY

I can't hear anything that doesn't sound like normal diesel engine noise.