[armend195]

Hello

Have a f20 120d automatic late 2012 with updated N47N/N47T engine which is supposed to be less frequent to chain snapping etc. 98 000 kms on the clock.

The car drives fine and feels smooth.
On startup there is no chain sound at all, nothing. When you drive off nothing but after about 10-15 minutes of driving and when the engine & oil heats up i get something that sounds like chain rattle. At idle is noticeable but the most at the 2000-25000 rpm range. And sometime i can feel it in the steering wheel/pedal/cabin like the "harshness" of the chain but im not sure if its just my imagination because of being afraid of the chain snapping.

I had a 2010 118d E87 prior to this and that also made small chain noices, it was even stage 2 and i used to push it hard and it managed 220k kms without any issues before i sold it.

So im wondering. Is it bad? Anyone had similar situation as me?
I've heard about changing the chain tensioner on the top chain as it can be reached from the back of the engine, is this a possible fix? Many say you should be worried when the chain sounds at cold start up, and mine does not.

What is possible and what is not?
Changing the chains is a big job, that requires engine to be taken out and costs a lot. What do you guys think?
Thanks!

[armend195]

I uploaded a video when the car is idling after driving for about an hour. The "rattle" is increasing with rpm increase.
Link to video:
https://gofile.io/d/fUuas5

[No one]

Hello.

I'm not sure I hear a rattle in that clip. Anyway, from your description, my wild guess (I am not a mechanic and have no similar experience) is that it should be a bearing going loose upon warming up. The tensioner you mentioned, perhaps.

[IJO]

Egr valve chattering?