Ancient H100i failing?

[dahgreatpro]

I'm still currently using an H100i from many years ago, stock fans are running fine. 

Pump is reading at ~2250 rpm and I have tried all fan speed ranges. My CPU seems to be at 90 degrees all the time under load (70-90 idle). When it is under load, the coolant temperature reaches up to 75 C (lol).

What are the potential causes of this? Is the cooler failing now even though the pump shows function in software?

 

[LeDoyen]

well.. it shows that the pump impeller is spinning, not that it's necesarely pushing anything ^^

Usual failure modes are permeation if your AIO is REALLY old, and you'd hear the pump screaming and probably a fair bit of sloshing and bubbling... or more commonly the fin stack on the coldplate is gunked up with residue from the coolant breaking down.

In that case the pump often still spins, but can't push much, if any flow, through the coldplate. In your case, i believe that's what may be happening.

You have just enough flow to avoid thermal shutdown, but the AIO is killing itself running toasty hot.

You could verify this by feeling the two tubes. In a normally working AIO, the temperature difference can be felt, but it's very small. In a clogged AIO, you'll have one fairly hot tube, and a cold one.

[dahgreatpro]

3 hours ago, LeDoyen said:

well.. it shows that the pump impeller is spinning, not that it's necesarely pushing anything ^^

Usual failure modes are permeation if your AIO is REALLY old, and you'd hear the pump screaming and probably a fair bit of sloshing and bubbling... or more commonly the fin stack on the coldplate is gunked up with residue from the coolant breaking down.

In that case the pump often still spins, but can't push much, if any flow, through the coldplate. In your case, i believe that's what may be happening.

You have just enough flow to avoid thermal shutdown, but the AIO is killing itself running toasty hot.

You could verify this by feeling the two tubes. In a normally working AIO, the temperature difference can be felt, but it's very small. In a clogged AIO, you'll have one fairly hot tube, and a cold one.

That makes sense, thank you for clarifying. There is a very significant difference in temperature. One the is almost so hot that it hurts to touch. There’s no excessive noise from the pump or coolant.

Was planning on building a new computer anyways but now I know I should replace the cooler on this old one too in the meantime

Edited June 2 by dahgreatpro

[c-attack]

Most likely a blockage as described above. Since these are all “No maintenance” sealed units, eventually stuff falls out of solution and this can happen. This is a much more typical end of life moment on that series than some type of obvious mechanical failure. Time to go shopping for a new AIO. You are near zero flow now, so temp is going to start building the moment you power on and then take hours to naturally cool off after shutdown.