Hi,
I bought a second hand Silvia. Had it shipped and decided to start off with descaling it before giving it a go. Followed instructions and when I turned on the pump It made sort of an irregular whistling noise. I had already seen that above the group head It looked very dirty. I decided to disassemble It just a little bit. I had hopes that It wouldn't be dirty above the 'shower'. Below are the pictures. Did not disassemble it much but enough to see that It was not only shallow dirt.

I cleaned this with professional detergent, backflushed thoroughly and then started over again. Same noise. Then I tried the steamer. Not the pressure I was expecting. Tried making Espresso. First one I threw away and then I tried. Good beans, not good taste. Felt like a bad extraction and sour/rancid taste. Tried the temperature surf. No difference.

Do you think there might still be hope? Do I need to disassemble all and clean from inside?

Kind regards,
Sebastian

On one of the pictures you see the coat and on the second one I have cleaned one surface.

Is the strange sound coming from the pump?

Hard to tell. It could as well be just outside the pump. I unscrewed the top to have a look inside. Still hard to judge.

Could be a leak. Or a bad pump.

You only need to loosen 3 more screws to take the back cover off, at which point you'll have much easier access to everything, and you can better figure out the source of the noise.