Aygo timing chain issues

[Cal5028]

Hi folks

This will be a slight continuation of my previous post, but I'd like to create an additional topic for this as we've narrowed the issue down. Therefore, if anyone ever has an issue with a slight metallic sound at around 2000-3000 rpm and a slight misfire, check this out.

The issue has been narrowed down to chain stretch. The car drives pretty much fine with no chain chatter when cold, but when at operating temperature (and after around 20 minutes), there's a slight audible chain chatter sound when you hit around 2000 rpm, and it clears perfectly up at 3000. It's apparently the chain stretching under heat, making the timing go just a little off on both the cams and the VVT. 

It will probably require a change of timing chain. The car has less than 40k miles. It's quite insane that this happens, but so be it - it sucks to change a timing chain, but if it has to be done, it has to be done.

Good luck out there, folks. Has anyone ever tried or heard of this?

[steveo3002]

a chain thats only stretched between 2-3k revs...doesnt sound right to me , its either stretched or it isnt

[Parts-King]

Nah, can't see that happening at all, more likely to be a tensioner or controller issue. Timing chain issues are almost unheard of, except in the most extreme cases of neglect (no oil changes) 

[Cal5028]

I absolutely agree! Even to this point, I find it weird as the metallic sound lessens after driving a long distance of say 3-4 hours. However, a lot of the vibrations stopped after we serviced the chain (checked for stretch and tightened it). 
What other things could cause a metallic-like ringing noise (bare audible but can be heard from inside cabin under load or when in neutral at 2000-3000 revs and ONLY happens with an engine at 1000% operating temperature?). The vibrations increase and when the engine is at 1000% operating temperature, it just doesn’t run as smoothly as when it’s say 80% up to operating temperature.