smps filter caps something loose inside

[diydidi]

I have a couple of filter caps 1000uF 200V taken from a wharfedale titan speaker.
When I shake these caps I can feel something large inside shaking against the cap outer shell. I measured with capacitance meter, it's fine; I measured with ESR meter, it's fine. Should I consider these caps faulty??

[Jazz P Bass]

Never had a rattler.
The plastic case is formed over the aluminum.
So something went wrong at the factory or something inside shrank.
I wouldn't trust it.

[Tom Phillips]

The rattling caps happen because some manufacturers use a standardized set of shell sizes and with some capacitance/voltage values the guts don’t completely fill the inside of the case as the illustration posted by Jazz P Base shows. If something is not right about the construction then the cap can rattle. This actually happens a lot with the later versions of the Sprague TVA series caps. The case size was kept large to give the look and fit of the originals but the cap guts are made with modern materials and are much smaller than the case leaving lots of empty space inside. That’s also why they are so much lighter than the old ones.

I don't use caps that rattle because the rattle indicates that something isn't secured properly inside the case. With the shock and vibration that amps are exposed to, a loose guts cap would be more prone to failure.