Peugeot 508 Hybrid 4 Belt Failure

[Stivem]

Hello, I had a problem with the belt, as it snapped. I replaced the tensioners and serviced the alternator by changing the bearings and installing a new belt. Now, my car is showing the error message "Check Engine - Repair is Needed," and after a few kilometers, the belt snapped again.
What could be the cause of this issue? Has anyone had a similar experience, and how did you resolve it?
Thanks in advance for help!

[PaulC5]

Is this the timing belt or the alternator drive belt ?

[Stivem]

Alternator drive belt sorry!

[wurlycorner]

If it's logged a message "Check Engine - Repair is needed" then it will have logged a fault code that should be read with a code reader, to give some direction.

But if the belt has snapped, then that will be a mechanical issue (which may or may not be related to what has set the code).

I'm not familiar with that engine/hybrid system at all, but unusually wikipedia https://en.wikipedia.org/wiki/PSA_HYbrid4 lists 'common problems' with it, which says the bearings in that alternator fail (causing the belt to snap - you've obviously already listed that) and then it also says the following:
"The accessories belt snaps unexpectedly soon after having been replaced with a new one. This is caused by improper tensioning of the belt"
So is that potentially the fault, second time around?

[PaulC5]

I am a bit confused. You have an identical topic for a DS5 hybrid, have you been unlucky that both your cars have the same fault or is it just one of them ?

[Stivem]

It broke a second time, you're right. So you think that improper tensioning led to the belt breaking, but could the quality of the belt also be a cause of the breakage? I'll definitely send the codes, perhaps that will provide additional clarification.

[Stivem]

Both have this problem

[Doom]

I'm using such car since 10 years. As I remember there are 2 important points:

1. Original PSA belt is a bit thicker and not very expensive so it's recommended to use OEM part

2. After belt change you have to adopt alternator via diagbox.

In case of alternator bearings - it's easy to check, just spin alternator wheel - it should be quiet. If you hear noise - you can replace bearing inside the alternator - or pay someone who rebuilding alternators. I did it in the past on my own. Provided some good quality parts and till now - 120k km it's still ok.