Air bubble or not ?

Th3GrayW01f · April 12, 2020

So i have got my first custom set up working using a EKA360G ( just the GPU loop ) and after 3 days of good temps i thought all was going well until i found what i think to be an air bubble on the output side of the GPU.

My loop is a follows Pump combo is LOWER than GPU but HIGHER than the in/out or the radiator. Top of radiator is higher than top of GPU. Flow is pump, radiator, GPU.

I cant change the set up much more than re pluming the flow as i am very limited on space.

I have attempted to bleed out the air by compressing the soft pipe and then venting the air out the GPU block blank-plug, this works but the air gap soon shows up again. with the pump off the air gap appears to move in to the GPU block but i cant see, when the pump is on the gap moves to the outlet side of the GPU.

Any adjective you can give would be great.

Thank you

Applefreak · April 12, 2020

Make sure the Reservoir / Pump unit is higher than the graphics card and radiator and then try running the pump at full speed (no pwm, just directly connected to the psu) and make sure there is enough liquid in there so the pump won't run dry. If you can get rid of the bubble but it comes again later, I'd suggest tightening those connectors and check for leaks.

If you are willing or able to remove the setup outside of the case and run on the psu only, then you would have an easier time removing that air. That radiator for example might still be filled to some part with air. That would cause the biggest delta in cooling performance. The air bubbles inside the cooler, as long as they are only bubbles and there is still fluid going through it, are not making that big of an impact on cooling.

Th3GrayW01f · April 12, 2020

So after a careful inspection of the loop i have sound a slight leak from the GPU output fitting.

After dissembling this section of the loop i have found a small aluminium cutting trapped under the factory fitted o-ring on the GPU fitting, After using a spare from the not used CPU block i have reassembled and so far there is no leak.

I spent 2-3 min working the air bubble out using the pre-mentioned method and so far there appears to be no air bubble.

I then ran the loop at a high stress to test cooling, using a GTX1080ti at 2020mhz clock and 6003mhz mem clock on a looping haven to reach 98% load. I reached a jump from 40c to 68c right away and then a steady climb as my pump and fans ramp up to full, i stopped after 11min of load test at 86c. The input to the gpu was showing approx 32c with the output showing close to 70c, the number are only good to with in 5c as there taken with a temp "gun". When the test was stopped the GPU showed a rapid drop to 55c and then a slower drop to 45c. ( The fans used are 3 Corsair Sp120 RGB Pro for the radiator )

I'm confident the loop work well for daily use and gaming but i am unimpressed with the temp climb over sustained load and don't know if this is normal or a indication of a fault. I feal like the GPU block is nor able to Transmit the heat to the coolant as well as i would expect or that perhaps i need to ramp up the flow.