Does anyone know what this grating sound could be?

[Rory Pattisson]

Recently bought a used 1 Series 116i SE (2007, 45000 Miles)

As we're heading into winter, it has started making a horrid sound on cold start, I've linked a video of it on youtube as an example. Other than that there isn't anything wrong, am just worried might be damaging something.

Engine oil is clean and has been replaced recently.

Here is a vid of the sound it's making: https://www.youtube.com/watch?v=NAkCi2iNW7Q



Any input would be appreciated. I have very little knowledge in this domain, am taking it to get looked by a mechanic regardless but any info would be fantastic.

[chazsandiego]

Just to try my hand at online diagnosis it sounds like the starter could be staying engaged a beat long.

However if the noise also occurs during rpm change I'd lean towards serpentine belt.

Good luck! Interested to see how it plays out.

Sent from my moto e6 using Tapatalk

[jclausen]

Engine belt tensioner noise

[Critter7r]

Engine belt tensioner noise

maybe ...

It sounds more like a spinning-pulley-with-a-dried-up-bearing noise (as opposed to the tensioner itself), so it's either the pulley on the tensioner, or one of the idler pulleys.