Pump Question

When I first got the Corsair kit, my pump consistently showed 3668/3750 on the tach reading. Today, I looked at the readings and the pump ranges all the way from 3250 to 3750. My CPU temps have also gone up about 1*C with occasional spikes of up to 3*C. E.g. I run S&M and idle is 34*C but full load is 46*C with sudden spikes up to 48*C and back down to 44*C then back to 46*C. My usual temps were 33/44. I'm worried that I may have the dreaded pump issue. Is this a sign of a failing pump, or am I overloading the 12V rail, or what's going on?? Is this normal?

NOTE: I did change rail configurations quite a bit while doing cable management and installing a new fan. I think it started after I installed the new intake fan. Any suggestions?

try with a old AT PSU just on the WC'er an see if same results?

mite be some some air still about in system

When I first got the Corsair kit, my pump consistently showed 3668/3750 on the tach reading. Today, I looked at the readings and the pump ranges all the way from 3250 to 3750. My CPU temps have also gone up about 1*C with occasional spikes of up to 3*C. E.g. I run S&M and idle is 34*C but full load is 46*C with sudden spikes up to 48*C and back down to 44*C then back to 46*C. My usual temps were 33/44. I'm worried that I may have the dreaded pump issue. Is this a sign of a failing pump, or am I overloading the 12V rail, or what's going on?? Is this normal?

 

NOTE: I did change rail configurations quite a bit while doing cable management and installing a new fan. I think it started after I installed the new intake fan. Any suggestions?

Hi dacris

The pump problem:

this was caused by the magnet in the pump stopping in between poles of the coils (centrifugal type pump) shant go into to technical details of how it works. and there wasnt enough inrush current to start it up again.

The new pumps allow full inrush to the motor now.

It then so appears that your pump is probably fine.

However its quite an odd problem. Its sureley your psu(maybe underated)

The pump however only requires 1.9A at 12V.

Can you see if you have an old 12v transformer about, check the polarity though, so you get the positive and negative the correct way round.

Then you can run the pump on its own 12V supply this way.

Dont forget to connect the blue tach wire back to your motherboard though.

You could use an old pc supply and short out pins to get it running on this.

I think its pins 13 and 14, but i would check this first.

My pump has run with readings from about 3150-3750 though,(could be my motherboards monitor is not very accurate????) but my temps seem quite constant however.

Ambient temps seem to be the major factor for watercooling.

Im running at 37/38 idle and about 43/44 on load.

This is pretty good as im cooling the cpu and gpu and northbridge(nb fain fan failed so it was a perfect opportunity to add this to the loop).

When i get a bit more time ii will probably use 2 loops in my system.

Im quite into this watercooling lark now...

Best of luck

PeteB

PeteB, what is the typical range of readings you get 30 mins after you start your computer? When I first start the system from a cold boot, my readings are constant between 3516 and 3668. Then, after half an hour, I check again and they're constantly going back and forth between 3308 and 3750. Like... 3308, 3375, 3444, 3516, 3590, 3668, 3750, and back down again. Each cycle takes less than two seconds.

EDIT: I tried moving my intake fan to the other rail but it didn't help. I have a dual-12V-rail 480W PSU with max. 32A on the 12V combined or 18A individually.

PeteB, what is the typical range of readings you get 30 mins after you start your computer? When I first start the system from a cold boot, my readings are constant between 3516 and 3668. Then, after half an hour, I check again and they're constantly going back and forth between 3308 and 3750. Like... 3308, 3375, 3444, 3516, 3590, 3668, 3750, and back down again. Each cycle takes less than two seconds.

 

EDIT: I tried moving my intake fan to the other rail but it didn't help. I have a dual-12V-rail 480W PSU with max. 32A on the 12V combined or 18A individually.

Hi dacris

After 30mins,

My pump readings are more stable than what your getting,

they flick between 3590 and 3668,

I could guess what the problem is (pump maybe sticking and therefore starting slow then speeding up slowing down again etc.

Which may affect the temp a little.

It appears if the pump is running between 3000 and 3750 its fine.

No excuse for it working properly of course. should be more stable than that.

Maybe it is an old style pump (how do you check???).

The typical fault of this pump is not the same as your experiencing though.

This is the best i can offer at the moment.

Perhaps someone has more or better suggestions.

The modded pumps seem to work fine as the one im using has worked floorlessly for some time now and very stable.

I wont go into air in the system and all that as you seem to know all about this area.

PeteB

Well I think if it was air bubles, wouldn't the pump spin *faster* when it encounters an air bubble?

Anyway, I will try to run it with nothing else plugged into the 12V rail and see if that makes a difference.

In that case, I don't think I'll worry about it. If the "normal" RPM is 3668, I'm still within +/- 10%. As long as the pump works and my temps are fine, I don't think it's anything to worry about.

Nothing wrong with worrying.

Whilst this is not a major problem, it would still niggle me, i would have to find out what the problem was.

I may soon upgrade to the mcp650 pump. This corsair cool kit has given me the watercooling bug. it was a perfect kit to introduce me to watercooling.

Upgrading it i guess was a natural progression.

I guess without a little experimenting im never going to know the best performance i can achieve.

I hope that a better pump(300gph i think) will improve things a little, or am i about at the maximum for watercooling??

Perhaps Corsair will do this for me and introduce a new COOL mark 2 or something????.

PeteB