Pump noise even after replacement

[Proximon]

I need some opinions here, mostly because I'm very short on time these days and would rather avoid the usual experimentation.

A few weeks ago my old Swiftech MCP655 started making a horrible racket. Just suddenly, out of the blue, like it was trying to drill it's way out of the XSPC dual bay res it's in. I figured it had finally died, and ordered up a Koolance PMP-450, just because it was the best price.

So, the other day I finally found time to do the swap. I pulled the old pump out, and sure enough the impeller felt rough and grindy when spun, and I could see wear/abrasion at the bottom of the bowl the impeller floats in. I put the new pump in.

Did my best to fill the loop before turning anything on, but it seemed like it wasn't filling like it should. Still, the bay res was full so I turned on the pump.... and the water didn't seem to move. I could feel the pump working. So, I cranked up the pump most of the way until it started whining. Still no bubbles or air moving out of the system... could it really simply be full? Maybe I got all the air out before I turned on the pump?

Two minutes later the new pump started making a similar loud noise. I unplugged everything and today I finally found time to pull the new pump out. IT SEEMS fine still.

So what is going on here? Do you think my loop could be actually plugged up somewhere? I want opinions before I spend the rest of my only full day off breaking everything down.

 

[CompGee]

Are you filling it outside? Dust can stop the pump from working right.

 

[jghaverty]

Its a centrifugal pump, so its going to make some noise. If its screeching, it means its running dry.

Just to dummy check (not an affront on your emotions 😀)
1) lots of these pumps have inserts on both sides. I assume you took them out?
2) do you have the pump hooked up right? Resevoir above the inlet?
3) is there a kink in any of the tubings? obstructions? If your last pump crapped itself, it could have released debris into somewhere.

Unfortunately, this means, you need to take all of it apart. Check the water block for obstruction. check all the tubes and fittings... better safe than sorry...

Dust can stop the pump from working right.

No.

 

[CompGee]

Have you oiled it?

 

[Proximon]

LOL

The pump is mounted on an XSPC dual bay res...
Scroll down to see what a disassembled pump looks like:
http://martinsliquidlab.org/2011/04/03/koolance-pmp-450-d5-vario-pump/

Basically, you get the pump, take it apart, and mount it in the res:
http://martinsliquidlab.org/2012/12/06/xspc-d5-dual-bay-reservoir-combo/2/

As near as I can tell the pump simply failed to create a flow because of an air block somewhere in the loop. The pump wasn't dry, as it was sitting right in the full res.

I drained the loop again, and re-filled it. Once I had everything back in place the loop went WHOOSH when I turned the pump on, just like it was supposed to the first time. Topped it off, tilted the case around to get the stray bubbles out, and let it leak test over night.

The water is clean and the temps are cool. There may be a little blockage at the CPU or GPU, but it will have to wait until vacation.

Thanks for the help though. I think the solution is to not have a rad as the highest item in the loop. Maybe this summer I will move that rad to the other side of the case.

 

[jghaverty]

Have you oiled it?

Do YOU typical add oil to your water cooled pumps designed to run a clean thermal liquid in which oil would degrade the entire purpose of the system?

Don't ever suggest anyone do this again unless you're positive about it. This would do more harm than good.

 

[CompGee]

Don't ever suggest anyone do this again unless you're positive about it. This would do more harm than good.

Please don't say that to CompGee again! 🙁
:/

 

[Proximon]

Sigh.