Noise dampening on radiator

[EulersK]

I posted a question a few weeks ago regarding a constant 'humming' coming from my water cooler. I was able to narrow it down to a specific cooler, but before I went to the manufacturer, I had a buddy of mine (who works in audio hardware design) come over with a meter whose name escapes me. He was able to point the meter to areas of the computer, and he narrowed it down to the radiator. Sure enough, when I removed the radiator from the case (with the whole system still on), the humming immediately went away. It was the vibration against the case all along! Much better scenario than the pump itself being bad.

Well, now comes the fun part. I have my radiator mounted in the following way: Case | Radiator | Fan. Note that since this is an AIO cooler, customization isn't a huge option here. That is, I can't set it up to be a pull rather than a push airflow unless I want a fan mounted on the outside of my case (I don't). I'd be able to flip the radiator 180 degrees, so air is blowing into the case, but I don't see how that would help at all. I've looked up ways to reduce the vibration - my knee jerk was to simply buy some rubber/silicon washers and call it a day. Apparently, according to my friend and several sources online, that will do very little due to the screws themselves transferring the vibration. He suggested these professional grade noise dampening screws that his work uses... to the tune of $10 a pop. No thank you. I've looked online and some have suggested using zip ties, and terrible aesthetics aside, this doesn't seem to be an option for this cooler.

So then, there must be a solution here. There's no way I'm the only one that has run into this problem, but hours of research online has yielded little more than frustration. Are rubber washers my only choice?

If it matters, here are the relevant parts: S340 case (radiator is mounted to the rear exhaust) with a EVGA Hybrid cooler on a GTX 980 ref card.

[Enderman]

its called a radiator gasket

buy one and put it between your case and the radiator

[colinreay]

1 minute ago, Enderman said:

its called a radiator gasket

This... Or, since the fan is probably vibrating against the radiator, which is vibrating against the case, you could go for something like a corsair sp120, or Fractal Venturi, or Noctua Industrial which has rubber pads to lessen vibration.

 

[Cactu]

Case|Fan|Rad|Fan now its push pull, and no fan on outside of case

[Enderman]

3 minutes ago, colinreay said:

This... Or, since the fan is probably vibrating against the radiator, which is vibrating against the case, you could go for something like a corsair sp120, or Fractal Venturi, or Noctua Industrial which has rubber pads to lessen vibration.

 

or add another gasket between the fan and the radiator

[EulersK]

3 minutes ago, Enderman said:

its called a radiator gasket

buy one and put it between your case and the radiator

THANK YOU. That's exactly what I need. Now let's hope this fixes the problem.

@colinreay: Good point, but since there is minimal noise (none that I can hear, actually) when the radiator is removed, even if you're right, the gasket looks like it would take care of the issue. I know what people have to say about AIO coolers, but at the very least, the stock fan seems to be quite nice. Not Noctua nice, of course, but very quiet for essentially being a freebie.

[EulersK]

UPDATE:

 

I got the gaskets in, and that immediately fixed the problem. Thanks, Enderman! For the record, what I bought came with two gaskets, so I put one between the case and the radiator as well as one between the radiator and the fan.

 

I have a nice and quiet PC now!