Nuova Simonelli Oscar brew sound

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Oskuk
Posts: 241
Joined: 13 years ago

#1: Post by Oskuk »

New member and straight away asking some help:

My half a year old Nuova Simonelli Oscar has got a new tendency of a pulsing sound. I think this is a resonance, but how to get rid of it? If I release some steam during a brew, it sometimes stops the sound, but not always. I made a short video on Youtube. This vid was with blind filter, a backflush -but the sound is the same on brewing a espresso. The sound has a variety of frequency, and the frequency mostly rises during brewing goes on.

Any ideas on cure -or at least a comment for the harmfulness of the symptom?

Oskuk (original poster)
Posts: 241
Joined: 13 years ago

#2: Post by Oskuk (original poster) »

Made new video. Seems that as Oscar pulses, the water is coming on left side drain. So it that valve defective?

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nixter
Posts: 785
Joined: 16 years ago

#3: Post by nixter »

Strange, possibly a problem with the over pressure valve? (OPV)

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Carneiro
Posts: 1153
Joined: 15 years ago

#4: Post by Carneiro »

OMG! I would tell "bad, bad pump", but if your neplax valve is opening, maybe this is the problem.

The neplax valve is a fixed expansion valve. I think the newer ones are made to open at 16 bar. But maybe the spring inside yours is bad and opening at some point around the maximum output of the pump and even worse - resonating. Very interesting!

I couldn't confirm the maximum pressure of the neplax I've used at my restored Oscar as the 3-way valve was opening around 12-13 bar (I think the 3-way is rated at 10 bar). But as I have installed an adjustable OPV right after the pump to keep things around 9 bar, I didn't care.

You should replace it. Maybe you could add an adjustable OPV and the flow restrictors to the group (best mod I've done to the machine)...

Márcio.

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nixter
Posts: 785
Joined: 16 years ago

#5: Post by nixter »

Or could it be that a bad pump is resonating high/low which is opening and closing the OPV?

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Carneiro
Posts: 1153
Joined: 15 years ago

#6: Post by Carneiro »

Yes, maybe... I've read again and Vesa says he got this problem extracting coffee too. Vesa, when you are pulling a shot and the pump makes the noise, do you get water from the valve too?

Márcio.

Oskuk (original poster)
Posts: 241
Joined: 13 years ago

#7: Post by Oskuk (original poster) »

Carneiro wrote: Vesa, when you are pulling a shot and the pump makes the noise, do you get water from the valve too?
I did a new test. But I did not have to. It's getting much worse. Hardly at all coffee, but plenty of the other show!
Bad video below -there is not that much light in Finland in this time a night.
I'd lean to think the valve is dead.

Oskuk (original poster)
Posts: 241
Joined: 13 years ago

#8: Post by Oskuk (original poster) »

Asked for the opv from Italy. They informed, after seeing the vids, that it still could be the 3-way solenoid who's to blame. So I opened and cleaned that, but no cure. So new "73012002 VALVOLA NEPLAX VITON 16BAR" is on it's way north. Let's hope that will be the answer.

jb-0101
Posts: 175
Joined: 12 years ago

#9: Post by jb-0101 »

Hi Oskuk - how did the new valve go? Can you post a picture of it?

Oskuk (original poster)
Posts: 241
Joined: 13 years ago

#10: Post by Oskuk (original poster) »

This expansion valve was the answer for me.

There was the pic on the other issue:

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